ARM: EXYNOS: Consolidate selection of PM_GENERIC_DOMAINS for Exynos4

Instead of repeating "select PM_GENERIC_DOMAINS" for all Exynos4
variants add relevant entry in the Kconfig section common to the
SoC series.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

arch/arm/mach-exynos/Kconfig

@@ -24,6 +24,7 @@ config ARCH_EXYNOS4
 	select HAVE_SMP
 	select MIGHT_HAVE_CACHE_L2X0
 	select PINCTRL
+	select PM_GENERIC_DOMAINS if PM
 	select S5P_DEV_MFC
 	help
 	  Samsung EXYNOS4 SoCs based systems
@@ -48,7 +49,6 @@ config CPU_EXYNOS4210
 	select ARCH_HAS_BANDGAP
 	select ARM_CPU_SUSPEND if PM
 	select PINCTRL_EXYNOS
-	select PM_GENERIC_DOMAINS if PM
 	select S5P_PM if PM
 	select S5P_SLEEP if PM
 	select SAMSUNG_DMADEV
@@ -61,7 +61,6 @@ config SOC_EXYNOS4212
 	depends on ARCH_EXYNOS4
 	select ARCH_HAS_BANDGAP
 	select PINCTRL_EXYNOS
-	select PM_GENERIC_DOMAINS if PM
 	select S5P_PM if PM
 	select S5P_SLEEP if PM
 	select SAMSUNG_DMADEV
@@ -74,7 +73,6 @@ config SOC_EXYNOS4412
 	depends on ARCH_EXYNOS4
 	select ARCH_HAS_BANDGAP
 	select PINCTRL_EXYNOS
-	select PM_GENERIC_DOMAINS if PM
 	select SAMSUNG_DMADEV
 	help
 	  Enable EXYNOS4412 SoC support