arm gpio drivers: make them 'depends on ARM'

We had a few drivers move from arch/arm into drivers/gpio, but they
don't actually compile without the ARM platform headers etc.  As a
result they were messing up allyesconfig on x86.

Make them depend on ARM.
Reported-by: NIngo Molnar <mingo@elte.hu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/gpio/Kconfig

@@ -89,24 +89,28 @@ config GPIO_IT8761E
 config GPIO_EXYNOS4
 	bool "Samsung Exynos4 GPIO library support"
 	default y if CPU_EXYNOS4210
+	depends on ARM
 	help
 	  Say yes here to support Samsung Exynos4 series SoCs GPIO library
 
 config GPIO_PLAT_SAMSUNG
 	bool "Samsung SoCs GPIO library support"
 	default y if SAMSUNG_GPIOLIB_4BIT
+	depends on ARM
 	help
 	  Say yes here to support Samsung SoCs GPIO library
 
 config GPIO_S5PC100
 	bool "Samsung S5PC100 GPIO library support"
 	default y if CPU_S5PC100
+	depends on ARM
 	help
 	  Say yes here to support Samsung S5PC100 SoCs GPIO library
 
 config GPIO_S5PV210
 	bool "Samsung S5PV210/S5PC110 GPIO library support"
 	default y if CPU_S5PV210
+	depends on ARM
 	help
 	  Say yes here to support Samsung S5PV210/S5PC110 SoCs GPIO library