meta-romulus: Add Mailbox Daemon

Change-Id: I711032e3d26cf1af8c51b11706bae2c9fcb40596
Signed-off-by: Lei YU <mine260309@gmail.com>
diff --git a/meta-ibm/meta-romulus/recipes-phosphor/mboxd/mboxd.bbappend b/meta-ibm/meta-romulus/recipes-phosphor/mboxd/mboxd.bbappend
new file mode 100644
index 0000000..8b6248a
--- /dev/null
+++ b/meta-ibm/meta-romulus/recipes-phosphor/mboxd/mboxd.bbappend
@@ -0,0 +1 @@
+MBOXD_FLASH_SIZE = "64M"