i965: Ignore anisotropic filtering in nearest mode.

i965: Ignore anisotropic filtering in nearest mode.

This fixes both Europa Universalis IV and Stellaris rendering on i965.
This was tested on SKL.

This fix was discovered by Jakub Szuppe at Stream HPC
(https://streamhpc.com/).

bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96958
bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=95530
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Tested-by: Dylan Baker <dylan@pnwbakers.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Cc: 17.1 <mesa-stable@lists.freedesktop.org>