The <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: zeal <zealcook@gmail.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Acked-by: NDaniel Silverstone <dsilvers@simtec.co.uk>
Acked-by: NSimtec Linux Team <linux@simtec.co.uk>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>