bonding: fix send_peer_notif overflow

Bonding send_peer_notif was defined as u8. Since commit 07a4ddec


("bonding: add an option to specify a delay between peer notifications").
the bond->send_peer_notif will be num_peer_notif multiplied by
peer_notif_delay, which is u8 * u32. This would cause the send_peer_notif
overflow easily. e.g.

  ip link add bond0 type bond mode 1 miimon 100 num_grat_arp 30 peer_notify_delay 1000

To fix the overflow, let's set the send_peer_notif to u32 and limit
peer_notif_delay to 300s.

Reported-by: Liang Li <liali@redhat.com>
Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2090053
Fixes: 07a4ddec

 ("bonding: add an option to specify a delay between peer notifications")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>