HID: sony: Use the controller Bluetooth MAC address as the unique value in the battery name string

Use the controller Bluetooth MAC address as the unique identifier in the
battery name string instead of the atomic integer that was used before.

Signed-off-by: Frank Praznik <frank.praznik@oh.rr.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>