HID: core: Add hid_hw_may_wakeup() function

Add a hid_hw_may_wakeup() function, which is the equivalent of
device_may_wakeup() for hid devices.

In most cases this just returns device_may_wakeup(hdev->dev.parent), but for
some ll-drivers this is not correct. E.g. usb_hid_driver instantiated hid
devices have their parent set to the usb-interface to which the usb_hid_driver
is bound, but the power/wakeup* sysfs attributes are part of the usb-device,
which is the usb-interface's parent.

For these special cases a new may_wakeup callback is added to
hid_ll_driver, so that ll-drivers can override the default behavior.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>