FROMGIT: drm/virtio: implement blob resources: blob display integration

SCANOUT_BLOB forwards the DRM framebuffer metadata to the host. The
modifier is intentionally left out -- it may be possible to query
the host for that.

We also assume one blob resource per DRM framebuffer.  That too is
an intentional simplification.

Signed-off-by: Gurchetan Singh <gurchetansingh@chromium.org>
Acked-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20200924003214.662-14-gurchetansingh@chromium.org


Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
(cherry picked from commit 0b0f1afe6cff06cf51a1435aa0089ce335df00b5
 git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git

 master)

BUG=b:171715474
TEST=compile

Change-Id: Iba952b9d4f8564c6a1a42659a221e910230c27e9
Signed-off-by: Guenter Roeck <groeck@chromium.org>
(cherry picked from commit 73c8f66222335bcec3d6f4cf50c2776424d226bd)