bonding: remove extraneous definitions from bonding.h

All of the symbols either only exist in bond_options.c or nowhere at
all. These symbols were verified to not exist in the code base by
using `git grep` and their removal was verified by compiling bonding.ko.

Signed-off-by: Jonathan Toppins <jtoppins@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>