mmc: mmc_mxc: Allow selection only for the correct platforms

Currently MMC_MXC driver can be selected by all i.MX devices.

Restrict its use only for the appropriate processors.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/host/Kconfig

@@ -311,7 +311,7 @@ config MMC_MSM
 
 config MMC_MXC
 	tristate "Freescale i.MX2/3 Multimedia Card Interface support"
-	depends on ARCH_MXC
+	depends on MACH_MX21 || MACH_MX27 || ARCH_MX31
 	help
 	  This selects the Freescale i.MX2/3 Multimedia card Interface.
 	  If you have a i.MX platform with a Multimedia Card slot,