isdn/gigaset: fix bas_gigaset interrupt read error handling

Rework the handling of USB errors in interrupt input reads
to clear halts correctly, delay URB resubmission after errors,
limit retries, and improve error recovery.

Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>