ARM: mx25: Add basic suspend/resume support

Tested basic suspend/resume on a mx25pdk:

$ echo enabled > /sys/class/tty/ttymxc0/power/wakeup
$ echo mem > /sys/power/state

Then press any key in the serial console and the system wakes up.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
diff --git a/arch/arm/mach-imx/common.h b/arch/arm/mach-imx/common.h
index 32b83f0..58a3846 100644
--- a/arch/arm/mach-imx/common.h
+++ b/arch/arm/mach-imx/common.h
@@ -66,6 +66,7 @@
 void imx_gpc_set_arm_power_in_lpm(bool power_off);
 void imx_gpc_set_arm_power_up_timing(u32 sw2iso, u32 sw);
 void imx_gpc_set_arm_power_down_timing(u32 sw2iso, u32 sw);
+void imx25_pm_init(void);
 
 enum mxc_cpu_pwr_mode {
 	WAIT_CLOCKED,		/* wfi only */