arm64: dts: ti: k3-am62p5-sk: Enable CPSW MDIO node

arm64: dts: ti: k3-am62p5-sk: Enable CPSW MDIO node

Enable the CPSW MDIO node, and link the pinctrl information to enable
ethernet on SK-AM62P.

Ethernet was unintentally broken on this board, even though these nodes
were already present, as enabling them was missed in the original
patch.

Fixes: c00504ea42c0 ("arm64: dts: ti: k3-am62p5-sk: Updates for SK EVM")
Signed-off-by: Ravi Gunasekaran <r-gunasekaran@ti.com>
Signed-off-by: Jai Luthra <j-luthra@ti.com>
Link: https://lore.kernel.org/r/20240201-am62p_cpsw_mdio-v1-1-05f758300f6e@ti.com
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>