build: Install bridge in libexec

Users aren't intended to run the server directly so it shouldn't be
included in their PATH.

Change-Id: Idc49664a7a07142ee27aac1318066bba6f67a6fd
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/phosphor-ipmi-kcs@.service.in b/phosphor-ipmi-kcs@.service.in
new file mode 100644
index 0000000..1d41541
--- /dev/null
+++ b/phosphor-ipmi-kcs@.service.in
@@ -0,0 +1,13 @@
+[Unit]
+Description=Phosphor IPMI KCS DBus Bridge
+Requires=phosphor-ipmi-host.service
+After=phosphor-ipmi-host.service
+
+[Service]
+Restart=always
+ExecStart=@BIN@ -c "%i"
+SyslogIdentifier=kcsbridged-%i
+
+[Install]
+WantedBy=multi-user.target
+RequiredBy=