Fix PLDM dependency string

After systemd daemon-reload an error was found:
  open_power.OCC.Control.service:7: Failed to add dependency on xyz.openbmc_project.PLDM, ignoring: Invalid argument

Change-Id: Id1c6ff9661347e3b7dc3e6d764dbe5ef4dc451bd
Signed-off-by: Chris Cain <cjcain@us.ibm.com>
diff --git a/service_files/org.open_power.OCC.Control.service b/service_files/org.open_power.OCC.Control.service
index d371d6a..05e5f81 100644
--- a/service_files/org.open_power.OCC.Control.service
+++ b/service_files/org.open_power.OCC.Control.service
@@ -6,8 +6,8 @@
 After=obmc-host-reset-running@0.target
 Wants=xyz.openbmc_project.Logging.service
 After=xyz.openbmc_project.Logging.service
-Wants=xyz.openbmc_project.PLDM
-After=xyz.openbmc_project.PLDM
+Wants=xyz.openbmc_project.PLDM.service
+After=xyz.openbmc_project.PLDM.service
 
 [Service]
 ExecStart=/usr/bin/openpower-occ-control