Merge branch 'mailbox-for-next' of git://git.linaro.org/landing-teams/working/fujitsu/integration

Pull more mailbox updates from Jassi Brar:
 "Device tree bindings and driver for TI's Message-Manager controller.

  Due to some last minute cosmetic changes, the driver was not included
  in the first pull request, otherwise the driver has been reviewed
  twice"

* 'mailbox-for-next' of git://git.linaro.org/landing-teams/working/fujitsu/integration:
  mailbox: Introduce TI message manager driver
  Documentation: dt: mailbox: Add TI Message Manager