gpio/mxc: 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 different gpio types, IMX1_GPIO
on i.mx1, IMX21_GPIO on i.mx21 and i.mx27, IMX31_GPIO on all other
i.mx SoCs.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/arch/arm/plat-mxc/devices/platform-gpio-mxc.c b/arch/arm/plat-mxc/devices/platform-gpio-mxc.c
index cf1b7fd..a7919a2 100644
--- a/arch/arm/plat-mxc/devices/platform-gpio-mxc.c
+++ b/arch/arm/plat-mxc/devices/platform-gpio-mxc.c
@@ -8,7 +8,7 @@
  */
 #include <mach/devices-common.h>
 
-struct platform_device *__init mxc_register_gpio(int id,
+struct platform_device *__init mxc_register_gpio(char *name, int id,
 	resource_size_t iobase, resource_size_t iosize, int irq, int irq_high)
 {
 	struct resource res[] = {
@@ -28,5 +28,5 @@
 	};
 
 	return platform_device_register_resndata(&mxc_aips_bus,
-			"gpio-mxc", id, res, ARRAY_SIZE(res), NULL, 0);
+			name, id, res, ARRAY_SIZE(res), NULL, 0);
 }