check-names: Consider crypto-sourced header files

Many identifiers come from Mbed Crypto. Teach check-names.sh to look in
the crypto submodule for identifiers, to avoid incorrect test results.
diff --git a/tests/scripts/check-names.sh b/tests/scripts/check-names.sh
index 90ecfd2..60018b5f 100755
--- a/tests/scripts/check-names.sh
+++ b/tests/scripts/check-names.sh
@@ -81,7 +81,7 @@
 
 printf "Likely typos: "
 sort -u actual-macros enum-consts > _caps
-HEADERS=$( ls include/mbedtls/*.h | egrep -v 'compat-1\.3\.h' )
+HEADERS=$( ls include/mbedtls/*.h crypto/include/mbedtls/*.h | egrep -v 'compat-1\.3\.h' )
 NL='
 '
 sed -n 's/MBED..._[A-Z0-9_]*/\'"$NL"'&\'"$NL"/gp \