gallium: set pipe_context uploaders in drivers (v3)

gallium: set pipe_context uploaders in drivers (v3)

Notes:
- make sure the default size is large enough to handle all state trackers
- pipe wrappers don't receive transfer calls from stream_uploader, because
  pipe_context::stream_uploader points directly to the underlying driver's
  stream_uploader (to keep it simple for now)

v2: add error handling to nv50, nvc0, noop
v3: set const_uploader

Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>
Tested-by: Edmondo Tommasina <edmondo.tommasina@gmail.com> (v1)
Tested-by: Charmaine Lee <charmainel@vmware.com>