For automated hardware testing, boot process control
via serial interface is needed. As such, in grub, serial
line support is added upon testmaster image install.
Also add a specific timeout to automatically start
the master image upon start of testing phase.
Tested on multiple hardware targets without issues.
Signed-off-by: Cristian Iorga <cristian.iorga@intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
