ARM: mach-imx: Kconfig: Do not select Babbage for MACH_IMX51_DT

When mx51 dt support was added it was necessary to select MACH_MX51_BABBAGE in
order to get the mx51 dt built without errors.

At that time, there was no pinctrl support for mx51 yet.

Currently there is no need to select MACH_MX51_BABBAGE anymore.
Reported-by: Matt Sealy <matt@genesi-usa.com>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

arch/arm/mach-imx/Kconfig

@@ -756,7 +756,6 @@ comment "i.MX51 machines:"
 
 config MACH_IMX51_DT
 	bool "Support i.MX51 platforms from device tree"
-	select MACH_MX51_BABBAGE
 	select SOC_IMX51
 	help
 	  Include support for Freescale i.MX51 based platforms