Move internal HMAC implementation into internal MAC driver

This is a temporary measure. Other operations in the PSA Core which rely
on this internal HMAC API should be rewritten to use the MAC API instead,
since they can then leverage accelerated HMAC should a platform provide
such acceleration support.

Signed-off-by: Steven Cooreman <steven.cooreman@silabs.com>
diff --git a/library/psa_crypto_mac.h b/library/psa_crypto_mac.h
index 4da60bf..d923511 100644
--- a/library/psa_crypto_mac.h
+++ b/library/psa_crypto_mac.h
@@ -23,6 +23,17 @@
 
 #include <psa/crypto.h>
 
+psa_status_t psa_hmac_setup_internal( psa_hmac_internal_data *hmac,
+                                      const uint8_t *key,
+                                      size_t key_length,
+                                      psa_algorithm_t hash_alg );
+
+psa_status_t psa_hmac_finish_internal( psa_hmac_internal_data *hmac,
+                                       uint8_t *mac,
+                                       size_t mac_size );
+
+psa_status_t psa_hmac_abort_internal( psa_hmac_internal_data *hmac );
+
 /** Calculate the MAC (message authentication code) of a message using Mbed TLS.
  *
  * \note The signature of this function is that of a PSA driver mac_compute