ARM: mxs: enable multiplatform build

Remove files that are not needed by multiplatform build, and make
necessary changes on Kconfig to enable multiplatform build.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
diff --git a/arch/arm/mach-mxs/Kconfig b/arch/arm/mach-mxs/Kconfig
index ecc4319..02e6935 100644
--- a/arch/arm/mach-mxs/Kconfig
+++ b/arch/arm/mach-mxs/Kconfig
@@ -1,5 +1,3 @@
-if ARCH_MXS
-
 config SOC_IMX23
 	bool
 	select ARM_AMBA
@@ -15,14 +13,18 @@
 	select HAVE_PWM
 	select PINCTRL_IMX28
 
-comment "MXS platforms:"
-
-config MACH_MXS_DT
-	bool "Support MXS platforms from device tree"
+config ARCH_MXS
+	bool "Freescale MXS (i.MX23, i.MX28) support"
+	depends on ARCH_MULTI_V5
+	select ARCH_REQUIRE_GPIOLIB
+	select CLKDEV_LOOKUP
+	select CLKSRC_MMIO
+	select CLKSRC_OF
+	select GENERIC_CLOCKEVENTS
+	select HAVE_CLK_PREPARE
+	select PINCTRL
 	select SOC_IMX23
 	select SOC_IMX28
+	select STMP_DEVICE
 	help
-	  Include support for Freescale MXS platforms(i.MX23 and i.MX28)
-	  using the device tree for discovery
-
-endif
+	  Support for Freescale MXS-based family of processors