This is preparation for supporing PM6125.

The HFSMPS is a BUCK type regulator with subtype 0x0a, same as the
existing HFS430 regulator.

Even though the HFSMPS and HFS430 share a type and subtype, the HFSMPS has
an updated register map, including different mode values, moved pull down
register, and different slew rate address and formula.

In addition to NORMAL (NPM), FAST (AUTO_LPM) and IDLE (LPM), the
regulator also supports RETENTION and AUTO_RM which are currently
unselectable by the driver.

The inspiration of this is taken from [1].

[1] https://source.codeaurora.org/quic/la/kernel/msm-5.4/commit/?h=kernel.lnx.5.4.r1-rel&id=d1220daeffaa440ffff0a8c47322eb0033bf54f5Signed-off-by: Iskren Chernev <iskren.chernev@gmail.com>
Link: https://lore.kernel.org/r/20220802221112.2280686-6-iskren.chernev@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>