mboxd: Mark the protocol as reset on shutdown

This is necessary for the host firmware to properly recover from a
daemon restart event, as it needs to re-perform the GET_INFO handshake
and re-establish any window it had active prior to the daemon
restarting.

While we're here, rename the symbol to align with the documentation.

Change-Id: I628d2ee5972177b7ad78392a86122d16104e7011
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
diff --git a/mboxd.c b/mboxd.c
index 745785e..f0deafe 100644
--- a/mboxd.c
+++ b/mboxd.c
@@ -439,6 +439,7 @@
 finish:
 	MSG_INFO("Daemon Exiting...\n");
 	context->bmc_events &= ~BMC_EVENT_DAEMON_READY;
+	context->bmc_events |= BMC_EVENT_PROTOCOL_RESET;
 
 	/* Alert on all supported transports */
 	protocol_events_put(context, mbox_ops);