insserv: define do_install_virtclass-native()

insserv: define do_install_virtclass-native()

[YOCTO #2812]

Since files installation dirs are DESTDIR/etc/, DESTDIR/sbin etc
in Makefile, not DESTDIR/${sysconfdir}/, DESTDIR/${sbindir}/, for
the native package, a prefix can not be inserted which is needed
when do the next step of install and do_populate_sysroot.

Now we define do_install_virtclass-native in which DESTDIR is
${D}/${STAGING_DIR_NATIVE}

Signed-off-by: Roy.Li <rongqing.li@windriver.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>