imx: iomux-v3: Add iomux-mx25.h

Allow usage of the imx-common/iomux-v3.h framework by including pad settings for
the i.MX25. The content of the file is taken from Linux kernel at commit
267dd34, plus the required changes to make it work in U-Boot.

Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
diff --git a/arch/arm/imx-common/Makefile b/arch/arm/imx-common/Makefile
index 1166488..a33c193 100644
--- a/arch/arm/imx-common/Makefile
+++ b/arch/arm/imx-common/Makefile
@@ -27,8 +27,11 @@
 
 LIB     = $(obj)libimx-common.o
 
+ifeq ($(SOC),$(filter $(SOC),mx25 mx5 mx6))
+COBJS-y	= iomux-v3.o
+endif
 ifeq ($(SOC),$(filter $(SOC),mx5 mx6))
-COBJS-y	= iomux-v3.o timer.o cpu.o speed.o
+COBJS-y	+= timer.o cpu.o speed.o
 COBJS-$(CONFIG_I2C_MXC) += i2c-mxv7.o
 endif
 ifeq ($(SOC),$(filter $(SOC),mx6 mxs))