Correct styling of Mbed TLS in documentation

Several bits of documentation were incorrectly styling Mbed TLS
as MbedTLS.

Signed-off-by: Thomas Daubney <thomas.daubney@arm.com>
diff --git a/tests/scripts/check_names.py b/tests/scripts/check_names.py
index f812929..86a7c09 100755
--- a/tests/scripts/check_names.py
+++ b/tests/scripts/check_names.py
@@ -941,7 +941,7 @@
             "This script confirms that the naming of all symbols and identifiers "
             "in Mbed TLS are consistent with the house style and are also "
             "self-consistent.\n\n"
-            "Expected to be run from the MbedTLS root directory.")
+            "Expected to be run from the Mbed TLS root directory.")
     )
     parser.add_argument(
         "-v", "--verbose",