tools/kvm: fix top level makefile

The top level tools/Makefile includes kvm_stat as a target in help, but
the actual target is missing.
Signed-off-by: Justin M. Forbes <jforbes@fedoraproject.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

tools/Makefile

@@ -86,10 +86,13 @@ tmon: FORCE
 freefall: FORCE
 	$(call descend,laptop/$@)
 
+kvm_stat: FORCE
+	$(call descend,kvm/$@)
+
 all: acpi cgroup cpupower gpio hv firewire lguest \
 		perf selftests turbostat usb \
 		virtio vm net x86_energy_perf_policy \
-		tmon freefall objtool
+		tmon freefall objtool kvm_stat
 
 acpi_install:
 	$(call descend,power/$(@:_install=),install)