ARM: dts: exynos: update dma node name with dtschema

Currently dma node name does not matches the pl330 dtschema and causes
dtbs_check to report below warning:

  'pdma@12680000' does not match '^dma-controller(@.*)?$'

Update the dma node name to match pl330 dtschema.

Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
Link: https://lore.kernel.org/r/20220130075520.49193-1-alim.akhtar@samsung.com


Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>