AM654 EVM base board has TI DP83867 PHY connected to external CPSW NUSS
Port 1 in rgmii-rxid mode.

Hence, add pinmux and Ethernet PHY configuration for TI am654 SoC Gigabit
Ethernet two ports Switch subsystem (CPSW NUSS).
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Tested-by: NMurali Karicheri <m-karicheri2@ti.com>
Tested-by: NPeter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>