MAINTAINERS: add missing files for bonding definition

The bonding entry did not include additional include files that have
been added nor did it reference the documentation. Add these references
for completeness.

Signed-off-by: Jonathan Toppins <jtoppins@redhat.com>
Link: https://lore.kernel.org/r/903ed2906b93628b38a2015664a20d2802042863.1651690748.git.jtoppins@redhat.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>