CHROMIUM: drivers: media: virtio: Fix reversed list ordering of supported formats.

The linked list was initialized in a fashion where elements with larger
indices were added to the beginning. This effectively reversed their order,
and resulted in wrong supported format combinations being reported.

To initialize a list in order of iteration, list_add_tail should be used
instead of list_add.

BUG=b:239897269
TEST=https://crrev.com/c/3920263

 reports the correct format combinations
     (h264: NV12/YV12, h265,vp8,vp9: YV12 only).

Signed-off-by: Tatsuyuki Ishi <ishitatsuyuki@google.com>
Change-Id: Ieffd49bc697e7f076393d7ca141d500bc39e07b5
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/3929881


Tested-by: Alexandre Courbot <acourbot@chromium.org>
Commit-Queue: Alexandre Courbot <acourbot@chromium.org>
Reviewed-by: Alexandre Courbot <acourbot@chromium.org>