[PATCH] ppc32: fix perf_irq extern on e500

Fixes e500 build and cleans up traps.c by moving perf_irq extern to
pmc.h.

Signed-off-by: Matt Porter <mporter@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/asm-powerpc/pmc.h b/include/asm-powerpc/pmc.h
index 2f3c3fc..5f41f3a 100644
--- a/include/asm-powerpc/pmc.h
+++ b/include/asm-powerpc/pmc.h
@@ -22,6 +22,7 @@
 #include <asm/ptrace.h>
 
 typedef void (*perf_irq_t)(struct pt_regs *);
+extern perf_irq_t perf_irq;
 
 int reserve_pmc_hardware(perf_irq_t new_perf_irq);
 void release_pmc_hardware(void);