panfrost: Flip point coords in hardware

panfrost: Flip point coords in hardware

On Bifrost, this is very easy: there's an RSD bit to Y-flip gl_PointCoord. It
should map perfectly to the Gallium bit. With this change, we no longer use
lower_pntc_ytransform on Bifrost, saving a bit of ALU when reading point
coordinates.

On Valhall, this is quite hard: the bit is in the framebuffer descriptor now!
That means it can't be changed in a batch. This is expected to be ok: on GLES
and VK, the origin is controlled only by the framebuffer orientation. It's a
bigger problem on big GL, where GL_POINT_SPRITE_COORD_ORIGIN can be set freely.
To cope, a tri-state data structure is used for the state tracking. This has a
failure case on Valhall: every draw toggling the coord origin. However, the
intention of the ORIGIN state bit is smoothing over coordinate system
differences; it should never /actually/ change once set. Until we see an app
doing something so stupid, I don't think we should worry about.

We need all the Valhall tri-state infrastructure for handling provoking vertices
on big GL anyway.

Signed-off-by: Alyssa Rosenzweig <alyssa@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16173>