ARM64: zynqmp: Remove DTC 1.4.2 warnings

DTC 1.4.2 reports these warnings:
Warning (unit_address_vs_reg): Node /amba_apu has a reg or ranges
property, but no unit name
Warning (unit_address_vs_reg): Node /amba has a reg or ranges property,
but no unit name
Warning (unit_address_vs_reg): Node /amba/usb@fe200000 has a unit name,
but no reg property
Warning (unit_address_vs_reg): Node /amba/usb@fe300000 has a unit name,
but no reg property
Warning (unit_address_vs_reg): Node
/amba/dma@fd4c0000/dma-video0channel@fd4c0000 has a unit name, but no
reg property
Warning (unit_address_vs_reg): Node
/amba/dma@fd4c0000/dma-video1channel@fd4c0000 has a unit name, but no
reg property
Warning (unit_address_vs_reg): Node
/amba/dma@fd4c0000/dma-video2channel@fd4c0000 has a unit name, but no
reg property
Warning (unit_address_vs_reg): Node
/amba/dma@fd4c0000/dma-graphicschannel@fd4c0000 has a unit name, but no
reg property
Warning (unit_address_vs_reg): Node
/amba/dma@fd4c0000/dma-audio0channel@fd4c0000 has a unit name, but no
reg property
Warning (unit_address_vs_reg): Node
/amba/dma@fd4c0000/dma-audio1channel@fd4c0000 has a unit name, but no
reg property
Warning (unit_address_vs_reg): Node /memory has a reg or ranges
property, but no unit name

This patch is fixing them.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>