HID: i2c-hid: Enable wakeup capability from Suspend-to-Idle

Many laptops can be woken up from Suspend-to-Idle by touchpad. This is
also the default behavior on other OSes.

However, if touchpad and touchscreen contact to each other when lid is
closed, wakeup events can be triggered inadventertly.

So let's disable the wakeup by default, but enable the wakeup capability
so users can enable it at their own discretion.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>