HID: asus: Add support for Fn keys on Asus ROG G752

This patch adds support for Fn keys on Asus ROG G752 laptop.
The report descriptor is broken so I fixed it.

Tested on an Asus G752VT.
Resent fix white space fixes

Signed-off-by: Maxime Bellengé <maxime.bellenge@gmail.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>