Add mbedtls_framework to mypy checks

Since this python module resides in the framework submodule we must
add an extra explicit path to it for mypy.

Signed-off-by: David Horstmann <david.horstmann@arm.com>
diff --git a/tests/scripts/check-python-files.sh b/tests/scripts/check-python-files.sh
index f3f4853..32b5baf 100755
--- a/tests/scripts/check-python-files.sh
+++ b/tests/scripts/check-python-files.sh
@@ -62,7 +62,7 @@
 
 echo
 echo 'Running mypy ...'
-$PYTHON -m mypy scripts/*.py tests/scripts/*.py ||
+$PYTHON -m mypy framework/scripts/mbedtls_framework/*.py scripts/*.py tests/scripts/*.py ||
   ret=1
 
 exit $ret