Input: cros_ec_keyb - mark cros_ec_keyb driver as wake enabled device.

Mark cros_ec_keyb has wake enabled by default. If we see a MKBP event
related to keyboard,  call pm_wakeup_event() to make sure wakeup
triggers are accounted to keyb during suspend resume path.

Signed-off-by: Ravi Chandra Sadineni <ravisadineni@chromium.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>