hsr: use netdev_master_upper_dev_link() when linking lower ports

hsr: use netdev_master_upper_dev_link() when linking lower ports

Unlike VLAN devices, HSR changes the lower device’s rx_handler, which
prevents the lower device from being attached to another master.
Switch to using netdev_master_upper_dev_link() when setting up the lower
device.

This could improves user experience, since ip link will now display the
HSR device as the master for its ports.

Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Link: https://patch.msgid.link/20250902065558.360927-1-liuhangbin@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>