pwrctl: add pgood state switching application

pgood_wait simply blocks until the power state changes to
the requested state.

The intent is for use from a systemd unit similar to nm-online.

Change-Id: Icf1e18f5d47d6eb2fc424b4614fd196ef3dfd6ee
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/op-pwrctl/pgood_wait/.gitignore b/op-pwrctl/pgood_wait/.gitignore
new file mode 100644
index 0000000..fbc938c
--- /dev/null
+++ b/op-pwrctl/pgood_wait/.gitignore
@@ -0,0 +1 @@
+pgood_wait