ARM: mxs: always build in device tree support

As the ultimate for mxs platform is to convert over to device tree,
let's start always building in device tree support for the platform.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Marek Vasut <marex@denx.de>

arch/arm/Kconfig

@@ -471,6 +471,7 @@ config ARCH_MXS
 	select COMMON_CLK
 	select HAVE_CLK_PREPARE
 	select PINCTRL
+	select USE_OF
 	help
 	  Support for Freescale MXS-based family of processors
 

arch/arm/configs/mxs_defconfig

@@ -22,6 +22,7 @@ CONFIG_BLK_DEV_INTEGRITY=y
 # CONFIG_IOSCHED_DEADLINE is not set
 # CONFIG_IOSCHED_CFQ is not set
 CONFIG_ARCH_MXS=y
+CONFIG_MACH_MXS_DT=y
 CONFIG_MACH_MX23EVK=y
 CONFIG_MACH_MX28EVK=y
 CONFIG_MACH_STMP378X_DEVB=y

arch/arm/mach-mxs/Kconfig

@@ -25,7 +25,6 @@ config MACH_MXS_DT
 	bool "Support MXS platforms from device tree"
 	select SOC_IMX23
 	select SOC_IMX28
-	select USE_OF
 	help
 	  Include support for Freescale MXS platforms(i.MX23 and i.MX28)
 	  using the device tree for discovery