percpu: make percpu symbols in powerpc unique

This patch updates percpu related symbols in powerpc such that percpu
symbols are unique and don't clash with local symbols.  This serves
two purposes of decreasing the possibility of global percpu symbol
collision and allowing dropping per_cpu__ prefix from percpu symbols.

* arch/powerpc/kernel/perf_callchain.c: s/callchain/cpu_perf_callchain/

* arch/powerpc/kernel/setup-common.c: s/pvr/cpu_pvr/

* arch/powerpc/platforms/pseries/dtl.c: s/dtl/cpu_dtl/

* arch/powerpc/platforms/cell/interrupt.c: s/iic/cpu_iic/

Partly based on Rusty Russell's "alloc_percpu: rename percpu vars
which cause name clashes" patch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@ozlabs.org

arch/powerpc/kernel/smp.c

@@ -232,7 +232,7 @@ struct thread_info *current_set[NR_CPUS];
 
 static void __devinit smp_store_cpu_info(int id)
 {
-	per_cpu(pvr, id) = mfspr(SPRN_PVR);
+	per_cpu(cpu_pvr, id) = mfspr(SPRN_PVR);
 }
 
 static void __init smp_create_idle(unsigned int cpu)