drm/msm/mdp5: Disable pingpong autorefresh at tearcheck init

If pp autorefresh is up (from bootloader splash), we will surely get
vblank and pp timeouts.  Ensure it is turned off.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
Link: https://lore.kernel.org/r/20210406214726.131534-4-marijn.suijten@somainline.org
Signed-off-by: Rob Clark <robdclark@chromium.org>