SYSTEMD_SERVICE doesn't need to be set conditionally, and units should be
installed if the systemd DISTRO_FEATURE is enabled, not if sysvinit isn't
enabled.
(From OE-Core rev: bb8a7b906204b25f07fe568883c2d605593c323c)
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>