[PATCH] IPMI: add pigeonpoint poweroff

X86 boards generally use ACPI for the power management interactions with the
BMC.  However, non-x86 boards need some help.  This patch adds the help for
the Motorola PigeonPoint-based IPMCs.

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