ARM: S5PC100: Move gpio support from plat-s5pc1xx to mach-s5pc100

Move gpio-lib support from plat-s5pc1xx to mach-s5pc100. Only basic gpio
functionality is now supported. Gpio interrupts are disabled temporarly
and will be added later.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>