virgl: use virgl_transfer in inline write

virgl: use virgl_transfer in inline write

Let's define a helper function and use it.

This commit also allows resources to be emitted into different command
buffers.

Like the ioctls, send 0 for layer_stride and stride.  If we actually
send the real values, there are various assumptions in virglrenderer
for non-1D buffers that may need to be modified.

Reviewed-by: Gert Wollny <gert.wollny@collabora.com>