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/setup-common.c

@@ -157,7 +157,7 @@ extern u32 cpu_temp_both(unsigned long cpu);
 #endif /* CONFIG_TAU */
 
 #ifdef CONFIG_SMP
-DEFINE_PER_CPU(unsigned int, pvr);
+DEFINE_PER_CPU(unsigned int, cpu_pvr);
 #endif
 
 static int show_cpuinfo(struct seq_file *m, void *v)
@@ -209,7 +209,7 @@ static int show_cpuinfo(struct seq_file *m, void *v)
 	}
 
 #ifdef CONFIG_SMP
-	pvr = per_cpu(pvr, cpu_id);
+	pvr = per_cpu(cpu_pvr, cpu_id);
 #else
 	pvr = mfspr(SPRN_PVR);
 #endif