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/list-enum-consts.pl b/tests/scripts/list-enum-consts.pl
index 21c25b3..cfef300 100755
--- a/tests/scripts/list-enum-consts.pl
+++ b/tests/scripts/list-enum-consts.pl
@@ -8,7 +8,7 @@
 
 -d 'include/mbedtls' or die "$0: must be run from root\n";
 
-@ARGV = grep { ! /compat-1\.3\.h/ } <include/mbedtls/*.h>;
+@ARGV = grep { ! /compat-1\.3\.h/ } <include/mbedtls/*.h crypto/include/mbedtls/*.h>;
 
 my @consts;
 my $state = 'out';