HID: wacom: Force new name for Wacom Intuos4 WL PTK-540WL

The name reported by Inutos4 WL connected by bluetooth is "PTK-540WL" and
to make it consistent with other Wacom devices it has to be converted to
"Wacom Intuos4 WL". It also makes userland applications aware that it's
a Wacom device.

This aligns naming of device to same used when this device is plugged into USB
port and controlled by USB wacom driver; and thus helps align userland logic to
route to apps like xf86-input-wacom.

Signed-off-by: Przemo Firszt <przemo@firszt.eu>
Reviewed-by: Chris Bagwell <chris@cnpbagwell.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>