intel/isl/gen4: Make depth/stencil buffers Y-Tiled

intel/isl/gen4: Make depth/stencil buffers Y-Tiled

Rendering to a linear depth buffer on gen4 is causing a GPU hang in the
CI system. Until a better explanation is found, assume that errata is
applicable to all gen4 platforms.

Fixes fbe01625f6bf2cef6742e1ff0d3d44a2afec003e
("i965/miptree: Share tiling_flags in miptree_create").

Reported-by: Mark Janes <mark.a.janes@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107248
Tested-by: Mark Janes <mark.a.janes@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>