dt-bindings: dma: atmel: Convert to json schema

dt-bindings: dma: atmel: Convert to json schema

Convert old text based binding to json schema.
Changes during conversion:
- Add the required properties `clock` and `clock-names`, which were
  missing in the original binding.
- Add a fallback for `microchip,sam9x7-dma` and `microchip,sam9x60-dma`
  as they are compatible with the dma IP core on `atmel,sama5d4-dma`.
- Update examples and include appropriate file directives to resolve
  errors identified by `dt_binding_check` and `dtbs_check`.

Signed-off-by: Charan Pedumuru <charan.pedumuru@microchip.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20241205-xdma-v1-1-76a4a44670b5@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>