HID: add extra hotkeys in Asus AIO keyboards

The Asus All-In-One PC has a wireless keyboard with wifi toggle,
brightness up, brightness down and display off hotkeys.

This patch adds suppoort for these hotkeys.

Signed-off-by: Keng-Yu Lin <kengyu@canonical.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>