[PATCH] s390: default storage key

Provide an easy way to define a non-zero storage key at compile time.  This is
useful for debugging purposes.

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>