Add support for TI TPS65219 PMIC.

Merge series from Jerome Neanne <jneanne@baylibre.com>:

This driver supports
- 3 Buck regulators and 4 LDOs
- low-power standby mode
- warm/soft reset
- basic fault handling (via interrupts).
- power button

Not implemented
- DVS

1-Regulators:
Full implementation and test
Visual check: cat /sys/kernel/debug/regulator/regulator_summary
Full validation requires userspace-consumer and virtual-regulator
LDO1 is not used and output can be probbed on TP84.