Merge tag 'omap-mailbox-for-v3.11' of git://github.com/sumananna/mailbox into omap...

Move OMAP Mailbox framework to drivers

The OMAP Mailbox driver framework is moved out of arch/arm folder
into drivers/mailbox folder, to re-enable building it and also serve
as a baseline for adapting to the new mailbox driver framework. The
changes mainly contain:
  - a minor bug fix and cleanup of mach-specific mailbox code
  - remove any header dependencies from plat-omap for multi-platform
    support
  - represent mailbox device data through platform data/hwmod attrs
  - move the omap mailbox code out of plat-omap/mach-omapX to
    drivers/mailbox folder.