KVM: ppc: enable KVM_TRACE building for powerpc

This patch enables KVM_TRACE to build for PowerPC arch. This means just
adding sections to Kconfig and Makefile.

Signed-off-by: Jerone Young <jyoung5@us.ibm.com>
Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
index 04e3449..2a5d439 100644
--- a/arch/powerpc/kvm/Makefile
+++ b/arch/powerpc/kvm/Makefile
@@ -4,9 +4,11 @@
 
 EXTRA_CFLAGS += -Ivirt/kvm -Iarch/powerpc/kvm
 
-common-objs = $(addprefix ../../../virt/kvm/, kvm_main.o coalesced_mmio.o)
+common-objs-y = $(addprefix ../../../virt/kvm/, kvm_main.o coalesced_mmio.o)
 
-kvm-objs := $(common-objs) powerpc.o emulate.o booke_guest.o
+common-objs-$(CONFIG_KVM_TRACE)  += $(addprefix ../../../virt/kvm/, kvm_trace.o)
+
+kvm-objs := $(common-objs-y) powerpc.o emulate.o booke_guest.o
 obj-$(CONFIG_KVM) += kvm.o
 
 AFLAGS_booke_interrupts.o := -I$(obj)