[RFC] implement arm64_adjust_dma_zone as arm32 does?

[Jisheng Zhang]

Dear Will, Catalin,

If one platform has one limitation only some banks are DMA-able, for example
0-2GB. Under arm32, we can set the dma_zone_size, then arm_adjust_dma_zone()
will set the correct dma zone for us. But under arm64, we can't do it.


Or set dma-range in dts, then use swiotlb to bounce?

Could you kindly please give one suggestion about how to handle this
situation?

Thanks in advance,
Jisheng