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/include/asm/smp.h

@@ -37,7 +37,7 @@ extern void cpu_die(void);
 extern void smp_send_debugger_break(int cpu);
 extern void smp_message_recv(int);
 
-DECLARE_PER_CPU(unsigned int, pvr);
+DECLARE_PER_CPU(unsigned int, cpu_pvr);
 
 #ifdef CONFIG_HOTPLUG_CPU
 extern void fixup_irqs(cpumask_t map);