regulator: add pm8008 pmic regulator driver

regulator: add pm8008 pmic regulator driver

The Qualcomm PM8008 is an I2C-controlled PMIC containing seven LDO
regulators.

The driver is based on a driver submitted by Satya Priya, but it has
been cleaned up and reworked to match the new devicetree binding which
no longer describes each regulator as a separate device.

This avoids describing internal details like register offsets in the
devicetree and allows for extending the implementation with features
like over-current protection without having to update the binding.

Specifically note that the regulator interrupts are shared between all
regulators.

Note that the secondary regmap is looked up by name and that if the
driver ever needs to be generalised to support regulators provided by
the primary regmap (I2C address) such information could be added to the
device-id table.

This also fixes the original implementation, which looked up regulators
by 'regulator-name' property rather than devicetree node name and which
prevented the regulators from being named to match board schematics.

Link: https://lore.kernel.org/r/1655200111-18357-8-git-send-email-quic_c_skakit@quicinc.com
Cc: Satya Priya Kakitapalli <quic_skakitap@quicinc.com>
Cc: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20240608155526.12996-12-johan+linaro@kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>