ARM: mxs: add initial pm support

This is a very initial pm support and basically does nothing.
With this pm support entry, drivers can start testing their own
pm functions.

Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
diff --git a/arch/arm/mach-mxs/Makefile b/arch/arm/mach-mxs/Makefile
index df501a8..6b26f02 100644
--- a/arch/arm/mach-mxs/Makefile
+++ b/arch/arm/mach-mxs/Makefile
@@ -2,6 +2,7 @@
 obj-y := clock.o devices.o gpio.o icoll.o iomux.o system.o timer.o
 
 obj-$(CONFIG_MXS_OCOTP) += ocotp.o
+obj-$(CONFIG_PM) += pm.o
 
 obj-$(CONFIG_SOC_IMX23) += clock-mx23.o mm-mx23.o
 obj-$(CONFIG_SOC_IMX28) += clock-mx28.o mm-mx28.o