gpio/mxc: Move Freescale MXC gpio driver to drivers/gpio

GPIO drivers are getting moved to drivers/gpio for cleanup and
consolidation.  This patch moves the plat-mxc driver.  Follow up
patches will clean it up and make it a fine upstanding gpio driver.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/arch/arm/plat-mxc/Makefile b/arch/arm/plat-mxc/Makefile
index a138787..d53c35f 100644
--- a/arch/arm/plat-mxc/Makefile
+++ b/arch/arm/plat-mxc/Makefile
@@ -3,7 +3,7 @@
 #
 
 # Common support
-obj-y := clock.o gpio.o time.o devices.o cpu.o system.o irq-common.o
+obj-y := clock.o time.o devices.o cpu.o system.o irq-common.o
 
 # MX51 uses the TZIC interrupt controller, older platforms use AVIC
 obj-$(CONFIG_MXC_TZIC) += tzic.o