After upgrading to poky pyro, generation of grub2 menuentry in grub2
became broken. Our init-install.sh script, origianlly coming from an old
poky version, was modified in poky
c2e63957d5abaa4bb10507da5ba16f01112d0bf5 to adapt to the fact that
/etc/grub.d/40_custom was not there anymore. We need to do the same,
otherwise the menyentry is not appended to the grub config and the
installed image won't boot correctly.
* take the baudrate for the grub serial console setting
from the kernel-cmdline which the system was booted from
* better parsing of the options which the install-script
gets from init
* Video Mode, VGA mode are not used right now and make it
empty right now.