perf top: Add ppc64 specific skip symbols and strip ppc64 . prefix

Filter out some ppc64 specific idle loop functions and remove
leading '.' on ppc64 text symbols.

Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: a.p.zijlstra@chello.nl
Cc: paulus@samba.org
LKML-Reference: <20090630230140.995643441@samba.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>