fix(intel): agilex bitstream pre-authenticate

HSD #15012010816: To add in bitstream pre-authentication checking.

Signed-off-by: Jit Loon Lim <jit.loon.lim@intel.com>
Change-Id: Ia8f1471a674ba16972927084f5fdc27c4ba93103
diff --git a/plat/intel/soc/common/include/socfpga_mailbox.h b/plat/intel/soc/common/include/socfpga_mailbox.h
index 1f4b2a4..3ab6f52 100644
--- a/plat/intel/soc/common/include/socfpga_mailbox.h
+++ b/plat/intel/soc/common/include/socfpga_mailbox.h
@@ -139,6 +139,7 @@
 #define SOFTFUNC_STATUS_CONF_DONE			(1 << 0)
 #define MBOX_CFGSTAT_STATE_IDLE				0x00000000
 #define MBOX_CFGSTAT_STATE_CONFIG			0x10000000
+#define MBOX_CFGSTAT_VAB_BS_PREAUTH			0x20000000
 #define MBOX_CFGSTAT_STATE_FAILACK			0x08000000
 #define MBOX_CFGSTAT_STATE_ERROR_INVALID		0xf0000001
 #define MBOX_CFGSTAT_STATE_ERROR_CORRUPT		0xf0000002