Clear HID0[en_attn] at CPU init time on PPC970.  Closes CVE-2006-4093.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>