mmc: sdhci-esdhc-imx: get rid of the uses of cpu_is_mx()

The patch removes all the uses of cpu_is_mx().  Instead, it utilizes
platform_device_id to distinguish the esdhc differences among SoCs.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: Wolfram Sang <w.sang@pengutronix.de>
Cc: Chris Ball <cjb@laptop.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Chris Ball <cjb@laptop.org>
diff --git a/arch/arm/plat-mxc/include/mach/devices-common.h b/arch/arm/plat-mxc/include/mach/devices-common.h
index 6ac2450..3beef77 100644
--- a/arch/arm/plat-mxc/include/mach/devices-common.h
+++ b/arch/arm/plat-mxc/include/mach/devices-common.h
@@ -277,6 +277,7 @@
 
 #include <mach/esdhc.h>
 struct imx_sdhci_esdhc_imx_data {
+	const char *devid;
 	int id;
 	resource_size_t iobase;
 	resource_size_t irq;