Enable branch coverage in basic_build_test.sh

Enable branch coverage output in basic_build_test.sh. This
includes enabling branch coverage output to the lcov make target,
which is disabled by default.

Signed-off-by: Dan Handley <dan.handley@arm.com>
diff --git a/Makefile b/Makefile
index 0a9640f..24d529a 100644
--- a/Makefile
+++ b/Makefile
@@ -106,11 +106,11 @@
 lcov:
 	rm -rf Coverage
 	lcov --capture --initial --directory library -o files.info
-	lcov --capture --directory library -o tests.info
-	lcov --add-tracefile files.info --add-tracefile tests.info -o all.info
-	lcov --remove all.info -o final.info '*.h'
+	lcov --rc lcov_branch_coverage=1 --capture --directory library -o tests.info
+	lcov --rc lcov_branch_coverage=1 --add-tracefile files.info --add-tracefile tests.info -o all.info
+	lcov --rc lcov_branch_coverage=1 --remove all.info -o final.info '*.h'
 	gendesc tests/Descriptions.txt -o descriptions
-	genhtml --title "mbed TLS" --description-file descriptions --keep-descriptions --legend --no-branch-coverage -o Coverage final.info
+	genhtml --title "mbed TLS" --description-file descriptions --keep-descriptions --legend --branch-coverage -o Coverage final.info
 	rm -f files.info tests.info all.info final.info descriptions
 
 apidoc: