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-power-start@.target b/common/recipes-core/systemd/obmc-targets/obmc-power-start@.target
new file mode 100644
index 0000000..d23c5e9
--- /dev/null
+++ b/common/recipes-core/systemd/obmc-targets/obmc-power-start@.target
@@ -0,0 +1,7 @@
+[Unit]
+Description=Power%i On
+After=obmc-power-start-pre@%i.target
+Wants={SYSTEMD_DEFAULT_TARGET}
+Conflicts=obmc-chassis-stop@%i.target
+RefuseManualStart=yes
+RefuseManualStop=yes