meta-phosphor: Add Mailbox Daemon

Change-Id: Ie65c83cfde93ae47c0dd1f9ffcfc37ce9566f18e
Tested: Built image and mboxd then ran on lanyang
	motherboard, checked the mailbox daemon on BMC,
	used instruction "ps -l" to check mailbox process
	status, the result like
	"mboxd --flash 64M --window-size 1M"
Signed-off-by: Brian Yang <yang.brianc.w@inventec.com>
2 files changed
tree: 6ae93ae8f35323cd6f5b12d48720e323facd7187
  1. conf/
  2. meta-lanyang/