i965: Fix texture border color on Broadwell.

i965: Fix texture border color on Broadwell.

The Gen7 sampler state code still works.  Increasing the alignment to
64 bytes makes bit 5 zero, which is good because it's now reserved.

Since we don't use the new filter bits, we can leave those as zero too,
which means we don't need to update the code to update the pointer.
(We probably should anyway, for clarity, but alas, another day.)

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