Register  gpio platform device on DA8XX boards.

While at it, group related include files together.
Signed-off-by: NPhilip Avinash <avinashphilip@ti.com>
[nsekhar@ti.com: remove SoC specific parts from this file.
		 fix compile warnings]
Signed-off-by: NSekhar Nori <nsekhar@ti.com>
Signed-off-by: NLad, Prabhakar <prabhakar.csengg@gmail.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>