platform/chrome: chromeos_tbmc: Report wake events

Mark chromeos_tbmc as wake capable and report wake events. This helps to
abort suspend on seeing a tablet mode switch event when kernel is
suspending. This also helps identifying if chromeos_tbmc is the wake
source.

Signed-off-by: Ravi Chandra Sadineni <ravisadineni@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>