riscv: dts: sophgo: remove address-cells from intc node

A recent submission [1] from Rob has added additionalProperties: false
to the interrupt-controller child node of RISC-V cpus, highlighting that
the new cv1800b DT has been incorrectly using #address-cells.
It has no child nodes, so #address-cells is not needed. Remove it.

Link: https://patchwork.kernel.org/project/linux-riscv/patch/20230915201946.4184468-1-robh@kernel.org/

 [1]
Fixes: c3dffa87 ("riscv: dts: sophgo: add initial CV1800B SoC device tree")
Reviewed-by: Jisheng Zhang <jszhang@kernel.org>
Acked-by: Chen Wang <unicorn_wang@outlook.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>