libcgroup: replace _virtclass-native with _class-native

The _virtclass-native is obsolete. Replace it with _class-native.

Signed-off-by: Yi Zhao <yi.zhao@windriver.com>
Signed-off-by: Joe MacDonald <joe_macdonald@mentor.com>

recipes-core/libcgroup/libcgroup_selinux.inc

-EXTRA_OECONF_virtclass-native = "--enable-pam=no"
+EXTRA_OECONF_append_class-native = " --enable-pam=no"
 
 do_install_append() {
 	test ! -f ${D}${base_libdir}/security/pam_cgroup.so.0.0.0 || {