regulator: dt-bindings: describe the PMU module of the WCN7850 package

The WCN7850 package contains discrete modules for WLAN and Bluetooth. They
are powered by the Power Management Unit (PMU) that takes inputs from the
host and provides LDO outputs. Extend the bindings for QCA6390 to also
document this model.

Acked-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Link: https://msgid.link/r/20240605121450.23697-3-brgl@bgdev.pl


Signed-off-by: Mark Brown <broonie@kernel.org>