i965: Add missing CACHE_NEW_WM_PROG dirty bit to WM pull constants.

i965: Add missing CACHE_NEW_WM_PROG dirty bit to WM pull constants.

Comparing brw_upload_vs_pull_constants and brw_upload_wm_pull_constants,
it became evident that something was amiss: the VS code had both
CACHE_NEW_VS_PROG and BRW_NEW_VERTEX_PROGRAM, while the WM code was
missing the CACHE_NEW_WM_PROG flag.

Not observed to fix anything, but likely necessary.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Paul Berry <stereotype441@gmail.com>