ARM: mach-imx: Select ARM_CPU_SUSPEND at ARCH_MXC level

Instead of selecting ARM_CPU_SUSPEND only for mx6, we can select it for
all SoCs from the ARCH_MXC family.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

arch/arm/mach-imx/Kconfig

 config ARCH_MXC
 	bool "Freescale i.MX family" if ARCH_MULTI_V4_V5 || ARCH_MULTI_V6_V7
 	select ARCH_REQUIRE_GPIOLIB
+	select ARM_CPU_SUSPEND if PM
 	select ARM_PATCH_PHYS_VIRT
 	select AUTO_ZRELADDR if !ZBOOT_ROM
 	select CLKDEV_LOOKUP
@@ -786,7 +787,6 @@ config SOC_IMX6Q
 	bool "i.MX6 Quad/DualLite support"
 	select ARCH_HAS_CPUFREQ
 	select ARCH_HAS_OPP
-	select ARM_CPU_SUSPEND if PM
 	select ARM_ERRATA_754322
 	select ARM_ERRATA_764369 if SMP
 	select ARM_ERRATA_775420