arm/imx: don't explicitly select GENERIC_GPIO

ARCH_REQUIRE_GPIOLIB selects GPIOLIB which in turn selects GENERIC_GPIO
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

arch/arm/Kconfig

@@ -309,7 +309,6 @@ config ARCH_MXC
 	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 	select ARCH_MTD_XIP
-	select GENERIC_GPIO
 	select ARCH_REQUIRE_GPIOLIB
 	select HAVE_CLK
 	select COMMON_CLKDEV