isdn: hisax: remove some dead code

The HISAX_HFC4S8S_PCIMEM code hasn't been able to compile since before
the start of git history.  I have deleted it.

There are also a few indenting mistakes where one side of the ifdef
wasn't indented correctly which I fixed as well.

Reported-by: Walter Harms <wharms@bfs.de>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>