Merge series " [PATCH v2 0/5]" from Dmitry Baryshkov <dmitry.baryshkov@linaro.org>:

On SM8250 MDSS_GDSC (and the rest of display clock controller) is
supplied power by MMCX power domain. Handle this link in GDSC code by
binding the power domain in dts file.

This patchset depends on [1]

Changes since v1:
 - Define fixed-regulator-domain regulator using power domain
   performance state for enabling/disabling.
 - Rework to use new fixed regulator type (fixed-regulator-domain)
   instead of controlling power domain directly from gdsc code.

Changes since RFC:
 - Fix naming of gdsc_supply_on/gdsc_supply_off functions
 - Fix detaching of solo gdsc's power domain in error handling code
 - Drop the dts patch, as respective display nodes are still not
   submitted to the mailing list.

[1]
https://lore.kernel.org/linux-arm-msm/20200927190653.13876-1-jonathan@marek.ca/