regulators: Add phosphor-regulators service dependencies

'regsctl' can't do anything useful until phosphor-regulators is running,
so add systemd unit dependencies to ensure it's started before
regulators-config and regulators-monitor-{enable,disable}.

While we're at it, change phosphor-regulators.service to be of type dbus
so we get a more meaningful check that it's really up and running, and
tweak the instantiation of ManagerObject so that it emits the necessary
signals.

Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Change-Id: I724e4f335c4347ad6789e2d68cfb58c6387e6073
diff --git a/services/phosphor-regulators-config.service b/services/phosphor-regulators-config.service
index 2193184..3da3cd6 100644
--- a/services/phosphor-regulators-config.service
+++ b/services/phosphor-regulators-config.service
@@ -1,5 +1,7 @@
 [Unit]
 Description=Phosphor Power Regulators Config
+Requires=phosphor-regulators.service
+After=phosphor-regulators.service
 Wants=obmc-power-start-pre@0.target
 Before=obmc-power-start-pre@0.target
 Before=op-power-start@0.service