net: dsa: microchip: Write switch MAC address differently for KSZ8463

KSZ8463 uses 16-bit register definitions so it writes differently for
8-bit switch MAC address.

Signed-off-by: Tristram Ha <tristram.ha@microchip.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20250725001753.6330-5-Tristram.Ha@microchip.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>