netifd: disable hairpin mode for brcm
After kick to 23.05 even we disable multicast_to_unicast for br-lan, netifd could still set multicast_to_unicast/hairpin for bridge port (when we set it in config/wireless). Skip it while we know hairpin introduce issues on brcm software.
Fix problem that stations could not connect to 2.4GHz AP with multicast_to_unicast set.
Signed-off-by: Janusz Dziedzic janusz.dziedzic@iopsys.eu