[SCSI] qla2xxx: Properly acknowledge IDC notification messages.

To ensure smooth operations amongst the FCoE and NIC side
components of the ISP81xx chip, the FCoE driver (qla2xxx) must
ensure the 10gb NIC driver (qlge) does not timeout waiting for
IDC (Inter-Driver Communication) acknowledgments.  The
acknowledgment requirements are trivial -- a simple mirroring of
incoming mailbox registers during the AEN to a process-context
capable mailbox command.

Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/scsi/qla2xxx/qla_fw.h b/drivers/scsi/qla2xxx/qla_fw.h
index 7abb045..ffff425 100644
--- a/drivers/scsi/qla2xxx/qla_fw.h
+++ b/drivers/scsi/qla2xxx/qla_fw.h
@@ -1402,6 +1402,8 @@
 #define MBA_IDC_NOTIFY		0x8101
 #define MBA_IDC_TIME_EXT	0x8102
 
+#define MBC_IDC_ACK		0x101
+
 struct nvram_81xx {
 	/* NVRAM header. */
 	uint8_t id[4];