Update spelling "mbed TLS" to "Mbed TLS"

The official spelling of the trade mark changed from all-lowercase "mbed"
to normal proper noun capitalization "Mbed" a few years ago. We've been
using the new spelling in new text but still have the old spelling in a
lot of text. This commit updates most occurrences of "mbed TLS":

```
sed -i -e 's/mbed TLS/Mbed TLS/g' $(git ls-files ':!ChangeLog' ':!tests/data_files/**' ':!tests/suites/*.data' ':!programs/x509/*' ':!configs/tfm*')
```

Justification for the omissions:

* `ChangeLog`: historical text.
* `test/data_files/**`, `tests/suites/*.data`, `programs/x509/*`: many
  occurrences are significant names in certificates and such. Changing
  the spelling would invalidate many signatures and tests.
* `configs/tfm*`: this is an imported file. We'll follow the upstream
  updates.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/scripts/bump_version.sh b/scripts/bump_version.sh
index 57ade94..b84308d 100755
--- a/scripts/bump_version.sh
+++ b/scripts/bump_version.sh
@@ -125,7 +125,7 @@
     sed -e "s/_VERSION_PATCH .\{1,\}/_VERSION_PATCH  $PATCH/" |    \
     sed -e "s/_VERSION_NUMBER .\{1,\}/_VERSION_NUMBER         $VERSION_NR/" |    \
     sed -e "s/_VERSION_STRING .\{1,\}/_VERSION_STRING         \"$VERSION\"/" |    \
-    sed -e "s/_VERSION_STRING_FULL .\{1,\}/_VERSION_STRING_FULL    \"mbed TLS $VERSION\"/" \
+    sed -e "s/_VERSION_STRING_FULL .\{1,\}/_VERSION_STRING_FULL    \"Mbed TLS $VERSION\"/" \
     > tmp
 mv tmp include/mbedtls/version.h
 
diff --git a/scripts/footprint.sh b/scripts/footprint.sh
index 4d7be7a..8e7f60a 100755
--- a/scripts/footprint.sh
+++ b/scripts/footprint.sh
@@ -17,7 +17,7 @@
 #
 # Purpose
 #
-# This script determines ROM size (or code size) for the standard mbed TLS
+# This script determines ROM size (or code size) for the standard Mbed TLS
 # configurations, when built for a Cortex M3/M4 target.
 #
 # Configurations included:
@@ -108,7 +108,7 @@
 fi
 
 log ""
-log "mbed TLS $MBEDTLS_VERSION$GIT_VERSION"
+log "Mbed TLS $MBEDTLS_VERSION$GIT_VERSION"
 log "$( arm-none-eabi-gcc --version | head -n1 )"
 log "CFLAGS=$ARMGCC_FLAGS"
 
diff --git a/scripts/generate_features.pl b/scripts/generate_features.pl
index 74a9527..6b1ef10 100755
--- a/scripts/generate_features.pl
+++ b/scripts/generate_features.pl
@@ -39,8 +39,8 @@
 
 my $feature_format_file = $data_dir.'/version_features.fmt';
 
-my @sections = ( "System support", "mbed TLS modules",
-                 "mbed TLS feature support" );
+my @sections = ( "System support", "Mbed TLS modules",
+                 "Mbed TLS feature support" );
 
 my $line_separator = $/;
 undef $/;
diff --git a/scripts/lcov.sh b/scripts/lcov.sh
index 8d141ee..6bba02f 100755
--- a/scripts/lcov.sh
+++ b/scripts/lcov.sh
@@ -51,7 +51,7 @@
     lcov --rc lcov_branch_coverage=1 --add-tracefile Coverage/tmp/files.info --add-tracefile Coverage/tmp/tests.info -o Coverage/tmp/all.info
     lcov --rc lcov_branch_coverage=1 --remove Coverage/tmp/all.info -o Coverage/tmp/final.info '*.h'
     gendesc tests/Descriptions.txt -o Coverage/tmp/descriptions
-    genhtml --title "mbed TLS" --description-file Coverage/tmp/descriptions --keep-descriptions --legend --branch-coverage -o Coverage Coverage/tmp/final.info
+    genhtml --title "Mbed TLS" --description-file Coverage/tmp/descriptions --keep-descriptions --legend --branch-coverage -o Coverage Coverage/tmp/final.info
     rm -f Coverage/tmp/*.info Coverage/tmp/descriptions
     echo "Coverage report in: Coverage/index.html"
 }
diff --git a/scripts/rename.pl b/scripts/rename.pl
index 9ea5f09..2214f37 100755
--- a/scripts/rename.pl
+++ b/scripts/rename.pl
@@ -17,8 +17,8 @@
 #
 # Purpose
 #
-# This script migrates application source code from the mbed TLS 1.3 API to the
-# mbed TLS 2.0 API.
+# This script migrates application source code from the Mbed TLS 1.3 API to the
+# Mbed TLS 2.0 API.
 #
 # The script processes the given source code and renames identifiers - functions
 # types, enums etc, as
@@ -88,7 +88,7 @@
     if( dir($filename)->parent eq $lib_include_dir ||
          dir($filename)->parent eq $lib_source_dir )
     {
-        die "Script cannot be executed on the mbed TLS library itself.";
+        die "Script cannot be executed on the Mbed TLS library itself.";
     }
 
     if( -d $filename ) { print STDERR "skip (directory)\n"; next }