input: sh_keysc: use enable/disable_irq_wake()

Modify the sh_keysc driver to use enable/disable_irq_wake()
during suspend and resume. These functions are used to enable
the sh_keysc interrupt in the interrupt controller so the
keypad can be used to wakeup the system from suspend.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>