ARM: 6136/1: ARCH_REQUIRE_GPIOLIB selects GENERIC_GPIO

The ARCH_REQUIRE_GPIOLIB config option will select GPIOLIB which
in turn will select GENERIC_GPIO.  Because of this, there is no
reason to do the select GENERIC_GPIO in arch/arm/Kconfig for the
architectures that have ARCH_REQUIRE_GPIOLIB.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>