ARM: EXYNOS: Clear ENABLE_WAKEUP_SW bit when entering suspend

Setting this bit to 0 causes the system to wait until suspended
to use the wakeup masks.  With it being set high previously,
masked interrupts were being received and processed before the
EINT_WAKEUP_MASK was configured.

Signed-off-by: Jonathan Kliegman <kliegs@chromium.org>
Signed-off-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>