With the potential modeset vs. modifiers issue covered by
commit 899c87af1f ("modesetting: unflip before any setcrtc() calls")
we can safely enable modifiers by default, at least on Intel
hardware where we know that things work properly.
I suppose the one open question is whether everything will work
correctly with wonky multi-GPU setups? I don't have one to test
myself.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>