powerpc, perf_counter: Fix performance counter event types

Sachin Sant reported these compiler errors:

 CC      arch/powerpc/kernel/power7-pmu.o
arch/powerpc/kernel/power7-pmu.c:297: error: PERF_COUNT_CPU_CYCLES undeclared here (not in a function)

Which happened because a last-minute rename of symbols crossed with
the Power7 support patch.

Fix this by using the new symbol names.

Reported-by: Sachin Sant <sachinp@in.ibm.com>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@ozlabs.org
LKML-Reference: <1244788494.5554.1.camel@ht.satnam>
Signed-off-by: Ingo Molnar <mingo@elte.hu>