ARM: dts: socfpga: fix dtbs_check warning for fpga-region

ARM: dts: socfpga: fix dtbs_check warning for fpga-region

soc (simple-bus): base_fpga_region: 'ranges' is a required property
	from schema $id: http://devicetree.org/schemas/simple-bus.yaml

base_fpga_region (fpga-region): $nodename:0: 'base_fpga_region' does not match
'^fpga-region(@.*|-([0-9]|[1-9][0-9]+))?$'
	from schema $id: http://devicetree.org/schemas/fpga/fpga-region.yaml

Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>