arm64: dts: ti: k3-j7200-common-proc-board: add mcu cpsw nuss pinmux and phy defs

The TI J7200 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 J7200 SoC MCU
Gigabit Ethernet two ports Switch subsystem (CPSW NUSS).

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Suman Anna <s-anna@ti.com>
Link: https://lore.kernel.org/r/20200923220938.30788-5-grygorii.strashko@ti.com