drm/tegra: Changes for v5.9-rc1

This set of patches contains a few preparatory patches to enable video
capture support from external camera modules. This is a dependency for
the V4L2 driver patches that will likely be merged in v5.9 or v5.10.

On top of that there are a couple of fixes across the board as well as
some improvements.

From a feature point of view this also adds support for horizontal
reflection and 180° rotation of planes.
Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Thierry Reding <thierry.reding@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200717162011.1661788-1-thierry.reding@gmail.com