list: introduce list_for_each_entry_from_reverse helper

Similar to list_for_each_entry_continue and its reverse variant
list_for_each_entry_continue_reverse, introduce reverse helper for
list_for_each_entry_from.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>