gallium: add PIPE_CAP_STREAM_OUTPUT_INTERLEAVE_BUFFERS

gallium: add PIPE_CAP_STREAM_OUTPUT_INTERLEAVE_BUFFERS

This allows the driver to signal that it can't handle random
interleaving of attributes across buffers. This is required for
ARB_transform_feedback3, and it's initialized to whatever the previous
value of PIPE_CAP_STREAM_OUTPUT_PAUSE_RESUME was except for nv50 where
it is disabled. Note that the proprietary drivers never expose
ARB_transform_feedback3 on any GT21x's (where nouveau previously did),
and after some effort I was unable to get it to work.

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>