Revert "HID: hid-asus.c: Maps key 0x35 (display off) to KEY_SCREENLOCK"

This reverts commit 2ea5999d.

As Dmitry Torokhov pointed out, the previous code (KEY_DISPLAY_OFF) is
actually correct. The real issue is that current desktop environments
don't deal it properly. Mapping it to another event does not solve the
issue.

So I'm reverting that change, keeping key 0x35 mapped to KEY_DISPLAY_OFF

Signed-off-by: Vinícius Angiolucci Reis <angiolucci@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>