hwdb: ieee1394-unit-function: remove entry for Cool Stream iSweet

hwdb: ieee1394-unit-function: remove entry for Cool Stream iSweet

IIDC specification describes configuration ROM without model field, thus
it's not possible to match any entry with vendor ID and model ID.
Current entry for Cool Stream iSweet can match any node and unit of
IIDC.

This commit removes the entry. I note that this model uses Texus
Instruments MC680-DCC as all-in-one chipset for video function in
IEEE 1394 bus.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>