nrf_security: cracen: Fix hmac block buffering calculation

Fix the hmac block buffering such that it works for all input sizes.

Signed-off-by: Markus Rekdal <markus.rekdal@nordicsemi.no>

subsys/nrf_security/src/drivers/cracen/cracenpsa/src/mac.c

@@ -248,7 +248,7 @@ static psa_status_t cracen_hmac_update(cracen_mac_operation_t *operation, const
 	 * adding as many input bytes as needed to get to be block aligned
 	 */
 	input_chunk_length = operation->bytes_left_for_next_block;
-	input_chunk_length += (input_length - input_chunk_length) & ~(block_size - 1);
+	input_chunk_length += ROUND_DOWN((input_length - input_chunk_length), block_size);
 	remaining_bytes = input_length - input_chunk_length;
 
 	/* forward the data to the driver */