systemd: Add syncronization points for OpenBMC

Add systemd syncronization targets to facilitate expressing
ordering dependencies.

Change-Id: I11d4fb2b8ade8d3ae74ddea44585153e2f59130f
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/common/recipes-core/systemd/obmc-targets/obmc-standby.target b/common/recipes-core/systemd/obmc-targets/obmc-standby.target
new file mode 100644
index 0000000..95044a4
--- /dev/null
+++ b/common/recipes-core/systemd/obmc-targets/obmc-standby.target
@@ -0,0 +1,9 @@
+[Unit]
+Description=Phosphor System - Standby
+Requires=multi-user.target
+RefuseManualStart=yes
+RefuseManualStop=yes
+AllowIsolate=yes
+
+[Install]
+WantedBy=multi-user.target