power: supply: bq27xxx: Create single chip data table

To support new features which require different data for each chip, we
unify the bq27xxx_regs and bq27xxx_battery_props tables into a single one.

No functional changes to the driver.
Signed-off-by: Liam Breck <kernel@networkimprov.net>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>