x86/platform: Add Eurobraille/Iris power off support

The Iris machines from Eurobraille do not have APM or ACPI support
to shut themselves down properly.  A special I/O sequence is
needed to do so.  This modle runs this I/O sequence at
kernel shutdown when its force parameter is set to 1.

Signed-off-by: Shérab <Sebastien.Hinderer@ens-lyon.org>
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
[ did minor coding style edits ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>