arm64: dts: lg: add dma-cells to pl330 node

dma-cells property is required for dma-controller.  Fixes dtbs_check
warnings like:

  dma@c1128000: '#dma-cells' is a required property

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Acked-by: Chanho Min <chanho.min@lge.com>
Link: https://lore.kernel.org/r/20220129175514.298942-1-krzysztof.kozlowski@canonical.com