ARM: dts: k3-j7200-common-proc-board-u-boot.dtsi: Fix dtc warnings

Fix following dtc warning by explicitly setting up #size-cells
and #address-cells when overriding node in -u-boot.dtsi

arch/arm/dts/k3-j7200-common-proc-board.dtb: Warning (reg_format):
/bus@100000/bus@28380000/mcu-navss/ringacc@2b800000:reg: property has
invalid length (80 bytes) (#address-cells == 2, #size-cells == 1)

Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>