drm/msm/dpu: drop DPU_PLANE_QOS_VBLANK_CTRL

Drop support for DPU_PLANE_QOS_VBLANK_CTRL flag. It is not used both
in upstream driver and in vendor SDE driver.

Reviewed-by: Jeykumar Sankaran <quic_jeykumar@quicinc.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/537907/
Link: https://lore.kernel.org/r/20230518222238.3815293-6-dmitry.baryshkov@linaro.org


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