feat(intel): support version 2 SiP SVC SMC function ID for mailbox commands

A separated SMC function ID of mailbox command
is introduced for the new format of SMC protocol.

The new format of SMC procotol will be started
using by Zephyr.

Signed-off-by: Siew Chin Lim <elly.siew.chin.lim@intel.com>
Signed-off-by: Sieu Mun Tang <sieu.mun.tang@intel.com>
Change-Id: I7996d5054f76c139b5ad55451c373f5669a1017f
diff --git a/plat/intel/soc/common/include/socfpga_mailbox.h b/plat/intel/soc/common/include/socfpga_mailbox.h
index 90b1fa6..1f4b2a4 100644
--- a/plat/intel/soc/common/include/socfpga_mailbox.h
+++ b/plat/intel/soc/common/include/socfpga_mailbox.h
@@ -113,6 +113,7 @@
 #define MBOX_WORD_BYTE					4U
 #define MBOX_RESP_BUFFER_SIZE				16
 #define MBOX_CMD_BUFFER_SIZE				32
+#define MBOX_INC_HEADER_MAX_WORD_SIZE			1024U
 
 /* Execution states for HPS_STAGE_NOTIFY */
 #define HPS_EXECUTION_STATE_FSBL			0
@@ -213,6 +214,8 @@
 			unsigned int *resp_len);
 int mailbox_send_cmd_async(uint32_t *job_id, uint32_t cmd, uint32_t *args,
 			unsigned int len, unsigned int indirect);
+int mailbox_send_cmd_async_ext(uint32_t header_cmd, uint32_t *args,
+			unsigned int len);
 int mailbox_read_response(uint32_t *job_id, uint32_t *response,
 			unsigned int *resp_len);
 int mailbox_read_response_async(uint32_t *job_id, uint32_t *header,