[media] msi3101: add debug dump for unknown stream data

Dump all unknown 'garbage' data - maybe we will discover someday if there
is something rational...
Also fix comment in USB frame description.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>