NVC0 will be able to share some of nv50's paths this way. This also makes
it the card-specific vram code responsible for deciding if a given set
of tile_flags is valid, rather than duplicating the allowed types in
nv50_vram.c and nouveau_gem.c
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
This is required on nv50 as we need to be able to have more precise control
over physical VRAM allocations to avoid buffer corruption when using
buffers of mixed memory types.
This removes some nasty overallocation/alignment that we were previously
using to "control" this problem.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>