net: dsa: microchip: Use PORT_CTRL_ADDR() instead of indirect function call

The indirect function call to dev->dev_ops->get_port_addr() is expensive
especially if called for every single register access, and only returns
the value of PORT_CTRL_ADDR() macro. Use PORT_CTRL_ADDR() macro directly
instead.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Tristram Ha <Tristram.Ha@microchip.com>
Cc: Woojung Huh <Woojung.Huh@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>