intel/dev: add warning on missing kernel uAPI for Gen8+

We carry those warnings in i965/anv. Let's have them here. Next commit
we remove some code from the drivers.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9052>
1 file changed