ARM: dts: qcom: switch to RPMh controlled PMIC regulators for Lahaina

Replace the stub-regulator device nodes for the PMIC PM8350,
PM8350C, and PMR735A regulators with rpmh-regulator device nodes.
This ensures that consumers are able to modify the physical state
of these PMIC regulators.

Keep VDD_CX, VDD_MXA, VDD_MXC, and VDD_MMCX always-on at Turbo
voltage level to avoid initialization issues before proxy voting
is available.

Leave the stub-regulator device for PM8350 LDO 7 in place as
RPMh does not yet support 2.7 V required by UFS.

Change-Id: Ie6357fb98d5568a9d601df93017f1220103d1ace