[PATCH] Add IPMI poweroff control to sysfs

Put the IPMI poweroff_powercycle parameter into sysfs.  This field is
dynamically settable and is valuable to have in sysfs.

Signed-off-by: Corey Minyard <minyard@acm.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>