[POWERPC] PS3: System-bus uevent

To allow userspace to automatically load modules, we need to hook up
uevent for ps3_system_bus devices.  I've used the form 'ps3:%d' with
the ps3_match_id, since that's what we use for matching drivers.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>