HID: enable dead keys on a belkin wireless keyboard

Belkin Wireless keyboard, model number F8E849KYBD, USB ID 1020:0006,
FCCID: K7SF8E849KYBD emits usages 0x03a-0x03c from Consumer usage page.
As of HUT v1.12, these are marked as reserved. If any conflict arises
later, the mapping could be made conditional on VID/PID.

Signed-off-by: Chris Clayton <chris2553@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>