hostmot2: support for up to 8 chars device names in sserial

Signed-off-by: Michael Geszkiewicz <micges@wp.pl>
hostmot2: properly support for up to 8 chars device names in sserial

Signed-off-by: Michael Geszkiewicz <micges@wp.pl>
hm2_eth: remove duplicated info about successfull hostmot2 registration

Signed-off-by: Michael Geszkiewicz <micges@wp.pl>