arm64: dts: exynos: align pl330 node name with dtschema

Fixes dtbs_check warnings like:

  pdma@15610000: $nodename:0: 'pdma@15610000' does not match '^dma-controller(@.*)?$'

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Link: https://lore.kernel.org/r/20220129175332.298666-1-krzysztof.kozlowski@canonical.com