staging: board: armadillo800eva: Board staging for sh_mobile_lcdc_fb

Add staging board support for the r8a7740-based armadillo800eva board
and add platform devices to allow in-tree continuous development of the
drivers on the armadillo800eva board.

When DT bindings are ready for theses drivers then the platform devices
in the armadillo800eva staging board code can easily be removed. Until
then we use platform devices to continuously improve the driver and
integrate code.

Added platform devices:
  - sh_mobile_lcdc_fb for the on-board LCD.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>