protocol: Add reset

Change-Id: Ie5c11e71312c30de1aa9ec14d963bde91545dc50
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
diff --git a/transport_mbox.c b/transport_mbox.c
index ec6d601..be2eba9 100644
--- a/transport_mbox.c
+++ b/transport_mbox.c
@@ -168,9 +168,12 @@
 int mbox_handle_reset(struct mbox_context *context,
 			     union mbox_regs *req, struct mbox_msg *resp)
 {
-	/* Host requested it -> No BMC Event */
-	windows_reset_all(context, NO_BMC_EVENT);
-	return lpc_reset(context);
+	int rc = context->protocol->reset(context);
+	if (rc < 0) {
+		return mbox_xlate_errno(context, rc);
+	}
+
+	return 0;
 }
 
 /*