[PATCH] drivers/isdn/hisax/: Convert to generic boolean-values

Signed-off-by: Richard Knutsson <ricknu-0@student.ltu.se>
Acked-by: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>