drm/amd: define new gfx12 uapi flags

define new gfx12 uapi flags

Signed-off-by: Marek Olšák <marek.olsak@amd.com>
Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Acked-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>