panfrost: Rename VARYING_POS to SNAP4

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Tested-by: Christian Hewitt <christianshewitt@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7352>
2 files changed