Bare-metal:  post complete GPIO monitor

This creates a service that monitors the post complete gpio, it
reenabled ipmi when gpio is deasserted. And at the startup it checks the
gpio and disable ipmi if it is asserted.

Tested:
1. reset host, ipmi is re-enabled
2. reboot bmc, ipmi is disabled after bmc booting up.

Change-Id: If52c72ce57e10f6efbb94fd3f0bdcb7655b48d61
Signed-off-by: John Wedig <johnwedig@google.com>
Signed-off-by: Yuxiao Zhang <yuxiaozhang@google.com>
diff --git a/.gitignore b/.gitignore
index 9dc3fde..4691b58 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,6 +7,7 @@
 !subprojects/metrics-ipmi-blobs/
 !subprojects/ncsid/
 !subprojects/nemora-postd/
+!subprojects/bare-metal-host-monitor/
 !subprojects/googletest.wrap
 !subprojects/phosphor-dbus-interfaces.wrap
 !subprojects/phosphor-logging.wrap