drm/amd/display: Enable fp16 also on DCE-11.0 - DCE-12. (v2)

drm/amd/display: Enable fp16 also on DCE-11.0 - DCE-12. (v2)

Testing on a Polaris11 gpu with DCE-11.2 suggests that it
seems to work fine there, so optimistically enable it for
DCE-11 and later.

v2: drop DCE 11.0 hunk.  Carrizo (DCE 11.0) has a HW bug where FP16
scaling doesn't work.  The upscale and downscale factors were
intended to block those FP16 cases and reject the commit but
nobody ever added those to atomic check.  Once those are added
to atomic check, this can be re-enabled.

Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>