ARM: imx: support arm power off in cpuidle for i.mx6sx

This patch introduces an independent cpuidle driver for
i.MX6SX, and supports arm power off in idle, totally
3 levels of cpuidle are supported as below:

1. ARM WFI;
2. SOC in WAIT mode;
3. SOC in WAIT mode + ARM power off.

ARM power off can save at least 5mW power.

This patch also replaces imx6q_enable_rbc with imx6_enable_rbc.

Signed-off-by: Anson Huang <b20788@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
diff --git a/arch/arm/mach-imx/pm-imx6.c b/arch/arm/mach-imx/pm-imx6.c
index 661ffcf..46fd695 100644
--- a/arch/arm/mach-imx/pm-imx6.c
+++ b/arch/arm/mach-imx/pm-imx6.c
@@ -205,7 +205,7 @@
 	writel_relaxed(val, ccm_base + CGPR);
 }
 
-static void imx6q_enable_rbc(bool enable)
+void imx6_enable_rbc(bool enable)
 {
 	u32 val;
 
@@ -359,7 +359,7 @@
 		 * RBC setting, so we do NOT need to do that here.
 		 */
 		if (!imx6_suspend_in_ocram_fn)
-			imx6q_enable_rbc(true);
+			imx6_enable_rbc(true);
 		imx_gpc_pre_suspend(true);
 		imx_anatop_pre_suspend();
 		/* Zzz ... */
@@ -368,7 +368,7 @@
 			imx_smp_prepare();
 		imx_anatop_post_resume();
 		imx_gpc_post_resume();
-		imx6q_enable_rbc(false);
+		imx6_enable_rbc(false);
 		imx6q_enable_wb(false);
 		imx6q_set_int_mem_clk_lpm(true);
 		imx6q_set_lpm(WAIT_CLOCKED);