power: supply: move HDQ interface for bq27xxx from w1 to power/supply

The HDQ interface driver should be in this folder just like the I2C
interface driver. Move this driver out of drivers/w1/slave and into
drivers/power/supply.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Acked-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>