anv: Emit DRAWING_RECTANGLE once at driver initialization

anv: Emit DRAWING_RECTANGLE once at driver initialization

Also, we don't actually need it for clipping because meta always colors
inside the lines and, for all other operations, the user is required to set
a scissor.  Since DRAWING_RECTANGLE stalls the GPU, we want to emit it as
little as possible.

Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>