Add handling for checkstop gpio

Add function to handle a checkstop gpio interrupt. Once interrupt
is received, wait an arbitrary time of 30s, and reboot the host
after that time if the gpio interrupt is still set and the system
state indicates the host is running.

Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>
diff --git a/hostcheckstop/Makefile b/hostcheckstop/Makefile
new file mode 100644
index 0000000..2d3b08d
--- /dev/null
+++ b/hostcheckstop/Makefile
@@ -0,0 +1,3 @@
+BINS=host_checkstop
+include ../gdbus.mk
+include ../rules.mk