ARM: substitute arch_idle()

Now that all implementations of arch_idle() are equivalent to cpu_do_idle()
we can just use the later directly and stop including mach/system.h.

Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-and-tested-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
diff --git a/arch/arm/mach-mxs/pm.c b/arch/arm/mach-mxs/pm.c
index fb042da..a9b4bbc 100644
--- a/arch/arm/mach-mxs/pm.c
+++ b/arch/arm/mach-mxs/pm.c
@@ -15,13 +15,12 @@
 #include <linux/kernel.h>
 #include <linux/suspend.h>
 #include <linux/io.h>
-#include <mach/system.h>
 
 static int mxs_suspend_enter(suspend_state_t state)
 {
 	switch (state) {
 	case PM_SUSPEND_MEM:
-		arch_idle();
+		cpu_do_idle();
 		break;
 
 	default: