chore(build_library/create_legacy_bootloader): remove old stuff

We don't need all of these args. Remove them.
feat(create_legacy_bootloader): add hvc0 on Xen

add console=hvc0 for systems that use pygrub/pvgrub by adding it to the
menu.lst files.
Merge pull request #52 from philips/add-hvc0-to-grub

Add hvc0 to grub