mbox: Update SRCREV after history re-writing

The SHA we were pointing disappeared from the repository.  Update to the
new HEAD.

Change-Id: I7851606e787a8d3d201f0fb27cbdbebab560b1f4
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/recipes-phosphor/mboxd/mboxd_git.bb b/recipes-phosphor/mboxd/mboxd_git.bb
index 1257f89..bb528a7 100644
--- a/recipes-phosphor/mboxd/mboxd_git.bb
+++ b/recipes-phosphor/mboxd/mboxd_git.bb
@@ -20,7 +20,7 @@
 SRC_URI += "file://99-aspeed-lpc-ctrl.rules"
 SRC_URI += "file://aspeed-lpc-ctrl-h.patch"
 
-SRCREV="e50e654bca8df8254c15849c793f9279adcb1182"
+SRCREV="ef0c8360065eba7f353f4ac866a1f6f86bf18cf4"
 
 PROVIDES += "mboxctl"