i965: Use tiling even for compressed textures.

i965: Use tiling even for compressed textures.

The code has no rationale for why we would force compressed textures to
be untiled, and it appears to work fine.  Git archeology indicates that
it's been that way dating back to when we first started tiling.

Improves performance in GLB27_TRex_C24Z16_FixedTimeStep at 1280x720 by
10.0529% +/- 0.573075% (n=12).  Improves performance in Xonotic by
4.56409% +/- 0.27965% (n=3).

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Eric Anholt <eric@anholt.net>