obmc-host-graceful-quiesce: ensure starts synch targets

As seen in other scenarios, the power off synchronization targets do not
always start in time when the obmc-host-graceful-quiesce@.target is
started. This can result the host being stopped before it has had the
chance to gracefully shut itself down.

Ensure the synchronization targets are started by adding them into the
target with 'Wants' relationships.

Tested:
- Booted system into hostboot, manually started the target and verified
  via the journal that the pldm-softpoweroff application completed prior
  to instructions stopping.

Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
Change-Id: Iede5194c24ad05467235419eaf0f343bccdffc1a
diff --git a/target_files/obmc-host-graceful-quiesce@.target b/target_files/obmc-host-graceful-quiesce@.target
index 6f2b8b5..b8b1685 100644
--- a/target_files/obmc-host-graceful-quiesce@.target
+++ b/target_files/obmc-host-graceful-quiesce@.target
@@ -1,4 +1,7 @@
 [Unit]
 Description=Graceful Quiesce Target
 After=multi-user.target
+Wants=obmc-host-stop-pre@%i.target
+Wants=obmc-host-stopping@%i.target
+Wants=obmc-host-stopped@%i.target
 Conflicts=obmc-chassis-poweroff@%i.target