[PARISC] Mark hisax and pcbit ISDN drivers as not for parisc

These drivers do not compile on big endian systems, and parisc
is big endian. Also mark some as broken on m68k as well.

Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>