i965/gen7: fix 3DSTATE_LINE_STIPPLE_PATTERN

The inverse repeat count should taks up bits 31:15 and is in U1.16.  Fixes
the "Restarting lines within a single Begin/End block" subtest of piglit
linestipple, and gets the other failing subtests much closer to passing.

v2: Rewrite commit message with more detailed piglit info (by anholt)

Reviewed-by: Eric Anholt <eric@anholt.net>
1 file changed