media: add missing blob structure field for tag id

The SUR40 can recognize specific printed patterns directly in hardware;
this information (i.e. the pattern id) is present but currently unused
in the blob structure.

Signed-off-by: Florian Echtler <floe@butterbrot.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>