Rename internal macro to pass check-names.sh

check-names.sh rejects MBEDTLS_XXX identifiers that are not defined in
a public header.
diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index a54cd73..9f7b5cb 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -1433,9 +1433,9 @@
 #if defined(static_assert)
 static_assert( ( MBEDTLS_PSA_KA_MASK_EXTERNAL_ONLY & MBEDTLS_PSA_KA_MASK_DUAL_USE ) == 0,
                "One or more key attribute flag is listed as both external-only and dual-use" );
-static_assert( ( MBEDTLS_PSA_KA_MASK_INTERNAL_ONLY & MBEDTLS_PSA_KA_MASK_DUAL_USE ) == 0,
+static_assert( ( PSA_KA_MASK_INTERNAL_ONLY & MBEDTLS_PSA_KA_MASK_DUAL_USE ) == 0,
                "One or more key attribute flag is listed as both external-only and dual-use" );
-static_assert( ( MBEDTLS_PSA_KA_MASK_INTERNAL_ONLY & MBEDTLS_PSA_KA_MASK_EXTERNAL_ONLY ) == 0,
+static_assert( ( PSA_KA_MASK_INTERNAL_ONLY & MBEDTLS_PSA_KA_MASK_EXTERNAL_ONLY ) == 0,
                "One or more key attribute flag is listed as both internal-only and external-only" );
 #endif