Do key usage policy extension when loading keys

Signed-off-by: gabor-mezei-arm <gabor.mezei@arm.com>
diff --git a/library/psa_crypto_slot_management.c b/library/psa_crypto_slot_management.c
index f90b0e3..3d10353 100644
--- a/library/psa_crypto_slot_management.c
+++ b/library/psa_crypto_slot_management.c
@@ -392,6 +392,10 @@
         if( status == PSA_ERROR_DOES_NOT_EXIST )
             status = PSA_ERROR_INVALID_HANDLE;
     }
+    else
+        /* Do the key usage policy extension. */
+        psa_extend_key_usage_flags( &(*p_slot)->attr.policy.usage );
+
     return( status );
 #else /* MBEDTLS_PSA_CRYPTO_STORAGE_C || MBEDTLS_PSA_CRYPTO_BUILTIN_KEYS */
     return( PSA_ERROR_INVALID_HANDLE );