perfcounters/powerpc: add support for POWER4 processors

Impact: more hardware support

This adds the back-end for the PMU on the POWER4 and POWER4+ processors
(GP and GQ).  This is quite similar to the PPC970, with 8 PMCs, but has
fewer events than the PPC970.

Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 49851e0..8e5e2c7 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -94,7 +94,7 @@
 obj64-$(CONFIG_AUDIT)		+= compat_audit.o
 
 obj-$(CONFIG_DYNAMIC_FTRACE)	+= ftrace.o
-obj-$(CONFIG_PERF_COUNTERS)	+= perf_counter.o ppc970-pmu.o \
+obj-$(CONFIG_PERF_COUNTERS)	+= perf_counter.o power4-pmu.o ppc970-pmu.o \
 				   power5-pmu.o power5+-pmu.o power6-pmu.o
 
 obj-$(CONFIG_8XX_MINIMAL_FPEMU) += softemu8xx.o