openpower-p9: Add delay in a reboot so mbox-reload can run

A quick fix to ensure that mbox-reload.service has a chance to run
after the power off and before the power on during a reboot.

An upcoming refactoring will remove the need for this patch.

Change-Id: Ieee0573e9bd4dec518361da9244d95a27357abd3
Signed-off-by: Matt Spinler <spinler@us.ibm.com>
3 files changed