ARM: 5969/1: nomadik: move gpio to plat-nomadik

Move the Nomadik GPIO driver to plat-nomadik so that it can also be used
on the Ux500 platform.

The mach-nomadik include/mach/gpio.h is replaced by one that includes
the one now in plat-nomadik, so that code doesn't need to include the
one in plat specifically, and can instead use <linux/gpio.h> as usual.

Acked-by: Alessandro Rubini <rubini@unipv.it>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>