ARM: 7045/1: mach-lpc32xx: break out GPIO driver specifics

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: Wolfram Sang <w.sang@pengutronix.de>
Cc: Barry Song <bs14@csr.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>