ir3_point_sprite() overrode the origin of a sprite coord,
we could just use a gallium helper instead.

Rename sprite_coord_mode into sprite_origin_upper_left,
which would be a better fit for a flag.

When deciding whether to take a fast path in
fd6_program_interp_state we should also take into
account sprite_origin_upper_left.

Delete ir3_point_sprite() since we removed the last
place it was used.

Fixes: a474d48e

 "freedreno/a6xx: use point-coord helper"

Signed-off-by: Danylo Piliaiev <dpiliaiev@igalia.com>