The "soc" node has ranges with addresses, so it is should have unit
address  to fix dtc W=1 warnings like:

  socfpga_stratix10.dtsi:128.6-636.4: Warning (unit_address_vs_reg): /soc: node has a reg or ranges property, but no unit name
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>