power: supply: bq25150 introduce the bq25150

Introduce the bq2515x family of chargers.

The BQ2515X family of devices are highly integrated battery management
ICs that integrate the most common functions for wearable devices
namely a charger, an output voltage rail, ADC for battery and system
monitoring, and a push-button controller.

Datasheets:
	bq25150 - http://www.ti.com/lit/ds/symlink/bq25150.pdf
	bq25155 - http://www.ti.com/lit/ds/symlink/bq25155.pdf



Signed-off-by: Ricardo Rivera-Matos <r-rivera-matos@ti.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>