sh: Fix up fallout from cpuidle changes.

Fixes up the pm_idle redefinition that was introduced with the earlier
cpuidle changes.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/kernel/idle.c

@@ -22,7 +22,7 @@
 #include <linux/atomic.h>
 #include <asm/smp.h>
 
-static void (*pm_idle)(void);
+void (*pm_idle)(void);
 
 static int hlt_counter;