BMC: Block BMC reboot during code update

- Create functions inside obmc-flash-bmc script to enable
  and disable reboots from command line.
- Create service files for enabling and disabling BMC reboots.
- The enable service will be called during the constructor of
  ActivationBlockTransition and disable service will be run during
  the destructor of ActivationBlockTransition.

Change-Id: Idcec12b2c1126e212ee861150c92aaacd23a1ace
Signed-off-by: Saqib Khan <khansa@us.ibm.com>
diff --git a/common/recipes-phosphor/flash/phosphor-software-manager/reboot-guard-enable.service b/common/recipes-phosphor/flash/phosphor-software-manager/reboot-guard-enable.service
new file mode 100644
index 0000000..4405e3d
--- /dev/null
+++ b/common/recipes-phosphor/flash/phosphor-software-manager/reboot-guard-enable.service
@@ -0,0 +1,8 @@
+[Unit]
+Description=Enable a guard that blocks BMC reboot
+
+[Service]
+Type=oneshot
+RemainAfterExit=no
+ExecStart=/usr/bin/env obmc-flash-bmc rebootguardenable
+SyslogIdentifier=obmc-flash-bmc