meta: Use common routine to configure fixed-function TNL state

meta: Use common routine to configure fixed-function TNL state

Also... glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0) *is* the identity
matrix, so drop the unnecessary call to _mesa_Ortho.

v2: Rename setup_ff_TNL_for_blit() to setup_ff_tnl_for_blit().  Seems
    silly to capitalize one out of two to three acronyms in the name
    (change by anholt, acked by idr).

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Brian Paul <brianp@vmware.com> (v1)
Reviewed-by: Eric Anholt <eric@anholt.net>