[PATCH] s390: introduce struct channel_subsystem

struct channel_subsystem encapsulates several per channel subsystem
properties, like status of chpids or the global path group id.

Signed-off-by: Cornelia Huck <cohuck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>