Modify the code path taken in `u_pipe_screen_get_param_defaults`
to call DRM to check if `PIPE_CAP_DMABUF` is supported. This is
required for overriding the behavior in `dri2_init_screen_extensions`
to support importing DMA bufs on drivers that don't support DRM, by
simply changing how `PIPE_CAP_DMABUF` is handled in their driver.
Reviewed-by: Mike Blumenkrantz <michael.blumenkrantz@gmail.com>
Reviewed-by: Eric Engestrom <eric@igalia.com>
Reviewed-by: Rob Clark <robdclark@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/21654>