We need to be able to build an sg table from our list of buddy blocks, so that we can later plug this into our ttm backend, and replace our use of the range manager. Signed-off-by: Matthew Auld <matthew.auld@intel.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210616152501.394518-2-matthew.auld@intel.com