ARM: 7032/1: plat-nomadik: break out GPIO driver specifics

The <[plat|mach]/gpio.h> file is included from upper directories
and deal with generic GPIO and gpiolib stuff. Break out the
platform and driver specific defines and functions into its own
header file.

Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Cc: Alessandro Rubini <rubini@unipv.it>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>