blorp: Emit a dummy 3DSTATE_WM prior to 3DSTATE_WM_HZ_OP

Cc: mesa-stable@lists.freedesktop.org
Suggested-by: Francisco Jerez <currojerez@riseup.net>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
(cherry picked from commit b6b2b278)
[Juan A. Suarez: resolve trivial conflicts]
Signed-off-by: Juan A. Suarez Romero <jasuarez@igalia.com>

Conflicts:
	src/intel/blorp/blorp_genX_exec.h