mmc: mxs-mmc: get rid of the use of cpu_is_xxx

The register HW_SSP_VERSION is broken for ssp version detection,
as the address of the register is different between imx23 and imx28.
Let's use platform_device_id to detect the device, so that the use
of cpu_is_xxx can be removed.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Chris Ball <cjb@laptop.org>
diff --git a/arch/arm/mach-mxs/include/mach/devices-common.h b/arch/arm/mach-mxs/include/mach/devices-common.h
index f2e3839..2b37689 100644
--- a/arch/arm/mach-mxs/include/mach/devices-common.h
+++ b/arch/arm/mach-mxs/include/mach/devices-common.h
@@ -89,6 +89,7 @@
 /* mmc */
 #include <mach/mmc.h>
 struct mxs_mxs_mmc_data {
+	const char *devid;
 	int id;
 	resource_size_t iobase;
 	resource_size_t dma;