Add a source plugin that support both EFI and legacy PC-Bios.
While using this plugin, both bootloaders configurations reside
in the same /boot partitions.
This plugin has very little code : to avoid code duplication,
we simply re-import bootimg-pcbios and bootmg-efi source and
call both their SourcePlugin methods.
(From OE-Core rev: c8545d54139c6c48bffd1dd1d39d79891626c6f7)
Signed-off-by: William Bourque <wbourque@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
