[POWERPC] PS3: Add logical performance monitor repository routines

Add repository routines for the PS3 Logical Performance Monitor.

Signed-off-by: Takashi Yamamoto <TakashiA.Yamamoto@jp.sony.com>
Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>