`wake_enabled` indicates cros_ec_resume() needs to call
disable_irq_wake() to undo enable_irq_wake() in cros_ec_suspend().

Determine `wake_enabled` in cros_ec_suspend() instead of
reset-after-used in cros_ec_resume().
Reviewed-by: NPrashant Malani <pmalani@chromium.org>
Signed-off-by: NTzung-Bi Shih <tzungbi@kernel.org>