i.MX2 family: Add GPIO multiplexing support

This patch adds GPIO multiplexing support for the imx1/mxc2
family of procesors.

Signed-off-by: Juergen Beisert <j.beisert@pengutronix.de>

diff --git a/arch/arm/plat-mxc/Makefile b/arch/arm/plat-mxc/Makefile
index e3cc25c..db66e9a 100644
--- a/arch/arm/plat-mxc/Makefile
+++ b/arch/arm/plat-mxc/Makefile
@@ -4,3 +4,5 @@
 
 # Common support
 obj-y := irq.o clock.o gpio.o time.o
+
+obj-$(CONFIG_ARCH_MX2) += iomux-mx1-mx2.o