drm/msm/hdmi: enable core-vcc/core-vdda-supply for 8996 platform

DB820c makes use of core-vcc-supply and core-vdda-supply, however the
driver code doesn't support these regulators. Enable them for HDMI on
8996 platform.

Fixes: 0afbe59e ("drm/msm/hdmi: Add basic HDMI support for msm8996")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Patchwork: https://patchwork.freedesktop.org/patch/488857/
Link: https://lore.kernel.org/r/20220609122350.3157529-8-dmitry.baryshkov@linaro.org


Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>