freedreno: enable a306

freedreno: enable a306

Whitelist adreno 306 (as found in msm8916/apq8016).  Works pretty much
out of the box, although the smaller GMEM size requires more tiles to
fit 1920x1080, so bump up the max # of tiles as well.

Since it is just whitelist + trivial change, it makes sense to land on
all the active release branches.

Note that a305c ends up with gpu-id "306", hence a306 ends up with
gpu-id of "307".  Apparently that is what happens when you let the
marketing dept name things.

Cc: "10.4" and "10.5" and "10.6" <mesa-stable@lists.freedesktop.org>
Signed-off-by: Rob Clark <robclark@freedesktop.org>