FROMGIT: drm/virtio: Spiff out cmd queue/response traces

Add a sequence # for more easily matching up cmd/resp, and the # of free
slots in the virtqueue to more easily see starvation issues.

v2: Fix handling of string fields as well

Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221130000841.318037-1-robdclark@gmail.com
(cherry picked from commit 2591939e
 git://anongit.freedesktop.org/drm/drm-misc drm-misc-next)

BUG=b:259691219
TEST=perfetto trace in arcvm with ToT perfetto

Change-Id: I629fc85b5fdbf083a3428fd51651df399de4d24f
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/4135259


Tested-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Chia-I Wu <olv@google.com>
Commit-Queue: Chia-I Wu <olv@google.com>
Commit-Queue: Rob Clark <robdclark@chromium.org>
Reviewed-by: Sean Paul <sean@poorly.run>
Auto-Submit: Rob Clark <robdclark@chromium.org>
Signed-off-by: Richard Fung <richardfung@google.com>