drm/msm/mdp5: drop vdd regulator

The "vdd" regulator was used by the mdp5 driver only on downstream
kernels, where the GDSC is represented as a regulator. On all current
kernels the MDSS_GDSC is implemented as the power domain, removing the
need for this regulator. Remove it from the mdp5 driver.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20211104003428.2205497-1-dmitry.baryshkov@linaro.org


Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>