arm64: dts: layerscape: use common pcs-handle property

pcsphy-handle already deprecated according to binding fsl,fman-dtsec.yaml.
Add new common pcs-handle at dts and fix below CHECK_DTBS warning.

arch/arm64/boot/dts/freescale/fsl-ls1043a-rdb.dtb: fman@1a00000: ethernet@e0000: 'pcs-handle' is a dependency of 'pcs-handle-names'
        from schema $id: http://devicetree.org/schemas/net/fsl,fman.yaml#



Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>