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>

drivers/clk/mxs/clk-imx28.c

@@ -148,22 +148,22 @@ static struct clk_lookup xbus_lookups[] __initdata = {
 };
 
 static struct clk_lookup ssp0_lookups[] __initdata = {
-	{ .dev_id = "mxs-mmc.0", },
+	{ .dev_id = "imx28-mmc.0", },
 	{ .dev_id = "80010000.ssp", },
 };
 
 static struct clk_lookup ssp1_lookups[] __initdata = {
-	{ .dev_id = "mxs-mmc.1", },
+	{ .dev_id = "imx28-mmc.1", },
 	{ .dev_id = "80012000.ssp", },
 };
 
 static struct clk_lookup ssp2_lookups[] __initdata = {
-	{ .dev_id = "mxs-mmc.2", },
+	{ .dev_id = "imx28-mmc.2", },
 	{ .dev_id = "80014000.ssp", },
 };
 
 static struct clk_lookup ssp3_lookups[] __initdata = {
-	{ .dev_id = "mxs-mmc.3", },
+	{ .dev_id = "imx28-mmc.3", },
 	{ .dev_id = "80016000.ssp", },
 };