regs: Add/install monitor enable service

Create a service file to call a method within the phosphor-regulators
binary to enable monitoring of the regulators. Add this service file to
be installed within the systemd services
directory(`/lib/systemd/system/`).

Tested:
    Monitoring is enabled after power on is complete
    Enablement of monitor does not block any other services

Signed-off-by: Matthew Barth <msbarth@us.ibm.com>
Change-Id: Ieee747c00ef748140511a50324201c11d9c8738f
diff --git a/services/phosphor-regulators-monitor-enable.service b/services/phosphor-regulators-monitor-enable.service
new file mode 100644
index 0000000..316a628
--- /dev/null
+++ b/services/phosphor-regulators-monitor-enable.service
@@ -0,0 +1,12 @@
+[Unit]
+Description=Phosphor Power Regulators Enable Monitoring
+Wants=obmc-power-on@0.target
+After=obmc-power-on@0.target
+Conflicts=obmc-chassis-poweroff@0.target
+
+[Service]
+RemainAfterExit=yes
+ExecStart=/usr/bin/regsctl monitor --enable
+
+[Install]
+WantedBy=obmc-chassis-poweron@0.target