Currently, files in /boot (other than /boot/kernel) are assigned to the
bootloader package using a filename match in mtree-to-plist.awk. This
causes some problems, most notably that debug info for userboot ends up
in the utilities-dbg package instead of bootloader-dbg.
Remove the path handling from mtree-to-plist and instead set PACKAGE
in the appropriate Makefiles to put these in the correct package.
While here, move userboot*.so from bootloader-dev to bootloader.
MFC after: 3 days