i965/gen7: Remove gratuitous dirty flags from WM and PS state.

i965/gen7: Remove gratuitous dirty flags from WM and PS state.

Commit b46dc45ceef3deb17ba2b0b4300eeb93e9cf7833 claimed that
NEW_POLYGONSTIPPLE is gratuitous, but somehow just changed comments
and whitespace instead of actually removing the flag.

While we're at it, 3DSTATE_PS doesn't appear to need NEW_LINE or
NEW_POLYGON either (those are in 3DSTATE_WM).  Also, 3DSTATE_WM
doesn't appear to need BRW_NEW_NR_WM_SURFACES or BRW_NEW_CURBE_OFFSETS
either (those are in 3DSTATE_PS).

NOTE: This is a candidate for the 7.11 branch.

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