update seabios to release 1.7.2.2

git shortlog from 1.7.2.1

Asias He (2):
      virtio-scsi: Pack struct virtio_scsi_{req_cmd,resp_cmd}
      virtio-scsi: Set _DRIVER_OK flag before scsi target scanning

Kevin O'Connor (1):
      Cache boot-fail-wait to avoid romfile access after POST.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

seabios @ d4f7d90f

-Subproject commit 88cb66ea542906ffff8a80ef397b9e3adbb33116
+Subproject commit d4f7d90f47462b4e8836899adc5060fbde5253e9