bq27x00: Add MODULE_DEVICE_TABLE

This patch adds MODULE_DEVICE_TABLE for module bq27x00_battery.

Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
Tested-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Rodolfo Giometti <giometti@linux.it>
Tested-by: Grazvydas Ignotas <notasas@gmail.com>