panfrost: Enable NV_primitive_restart on Valhall

Unlike literally every other mesa/st emulation, for some inexplicable reason we need to pretend to support the CAP and then set a different EMULATE cap instead of the emulation keying off the lack of support for the CAP. Set the CAPs accordingly so we get NV_primitive_restart (with emulation of non-fixed indices).

This gets Mesa to advertise GL 3.1 on Mali-G57 as intended.

Fixes: 30c14f54 ("panfrost: Disable PIPE_CAP_PRIMITIVE_RESTART on v9") Signed-off-by: Alyssa Rosenzweig alyssa@collabora.com