regulator: Add TPS65185 driver

regulator: Add TPS65185 driver

Add a driver for the TPS65185 regulator. Implement handling of the various
gpio pins. Because the PWRUP (=enable) pin functionality can be achieved
by just using two bits instead, just ensure that it is set to a stable
value.
Implement the pair of symmetric LDOs as a single regulator because they
share a single voltage set register. As the VCOM regulator sits behind that
machinery, just define that one as a supply.
For simplicity, just add the temperature sensor (depending on external NTC)
directly.

There is a mechanism to measure some kick-back voltage during a defined EPD
operation, to calibrate the VCOM voltage setting and store that
non-volatile in the chip to be the power up default setup. That is not
implemented yet in the driver, but that also means that there is a
non-factory default value in these registers after power-up.

Tested-by: Josua Mayer <josua.mayer@jm0.eu>
Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Link: https://patch.msgid.link/20260102-tps65185-submit-v3-2-23bda35772f2@kemnade.info
Signed-off-by: Mark Brown <broonie@kernel.org>