sh: Remove cpu_idle_wait()

cpuidle uses generic kick_all_cpus_sync() now. Remove the unused code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Link: http://lkml.kernel.org/r/20120507175652.461648208@linutronix.de