classes-systemd: Add link variable

Add new variable SYSTEMD_LINK for arbitrary link installation
in the ${systemd_system_unitdir} namespace.

For example, assume a template foo@.target exists and an instance of
this template is desired.  To describe this:

SYSTEMD_LINK_${PN} +=
  "foo@.target:foo@instance.service"

Change-Id: I8bb443e71d8eed44d4704c58167e1ff19bdfe2f5
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
1 file changed
tree: c3873a5f8fb4a1aa50c9268fdde7ea61ed05c384
  1. classes/
  2. common/
  3. conf/
  4. COPYING.apache-2.0
  5. COPYING.MIT
  6. LICENSE