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/meta-phosphor/common/recipes-phosphor/dbus/obmc-mapper/org.openbmc.ObjectMapper.service b/meta-phosphor/common/recipes-phosphor/dbus/obmc-mapper/org.openbmc.ObjectMapper.service
index ff863ea..b397e2f 100644
--- a/meta-phosphor/common/recipes-phosphor/dbus/obmc-mapper/org.openbmc.ObjectMapper.service
+++ b/meta-phosphor/common/recipes-phosphor/dbus/obmc-mapper/org.openbmc.ObjectMapper.service
@@ -1,5 +1,6 @@
 [Unit]
 Description=Phosphor OpenBMC DBus service management daemon
+Before=obmc-mapper.target
 
 [Service]
 Restart=always