arch: arm64: dts: improve the overlay used to updating FPGA image

- remove unnecessary #address-cells and #size-cells property
- correct #address-cells and #size-cells property

Signed-off-by: Meng Li <Meng.Li@windriver.com>
Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
Signed-off-by: Liwei Song <liwei.song@windriver.com>