Merge branch 'linux-4.20' of git://github.com/skeggsb/linux into drm-fixes

Three fixes:
tegra regression fix
display flushing fix
mst cleanup fix.

Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Ben Skeggs <skeggsb@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/CACAvsv7WCPzjQZonk+eS1FgEUKirz-4LOrVpMUVMM=D-GjbVpg@mail.gmail.com