drm/msm/mdp5: add missing LM flush bits

For some reason, layer-mixer 3 and 4 were missing.  LM3 is used for
writeback on 8x16.

Signed-off-by: Rob Clark <robdclark@gmail.com>
This commit is contained in:
Rob Clark 2018-02-19 08:29:33 -05:00
commit 583c13fd77