drm/msm/hdmi: drop hpd_regs usage on 8x74/8084

drm/msm/hdmi: drop hpd_regs usage on 8x74/8084

The MSM HDMI driver has support for hpd_regs on 8x74/8084: supply
regulators that are to be enabled for HPD to work. Currently these
regulators contain the hpd_gdsc, which was replaced by the power-domains
support and hpd-5v/hpd-5v-en, which are not used by the chip itself.
They power up the ESD bridge.
However it is a separate device which should be represented separately
in the device tree.
None of upstreamed devices support these properties. Thus drop support
for them from the HDMI driver.

Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/488860/
Link: https://lore.kernel.org/r/20220609122350.3157529-10-dmitry.baryshkov@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>