ARM: 7044/1: mach-lpc32xx: move LPC32XX GPIO driver to GPIO subsystem

As per example from the other ARM boards, push the LPC32XX
GPIO driver down to the GPIO subsystem so it can be consolidated.

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>