Staging: asus_oled: Add defines for asus vendor_id and device_id to be consistent with hid-ids.h

This almost trivial patch replaces the hardcoded values for the vendor and
device ids with defines, as they are used in drivers/hid/hid-ids.h

For me this seems to be more consistent, however as drivers/hid/hid-ids.h
is not within the default include directory I had to redefine the defines here
(maybe move the hid-ids.h to include/linux ?)

Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>