dt-bindings: net: can: atmel: Convert to json schema

dt-bindings: net: can: atmel: Convert to json schema

Convert old text based binding to json schema.
Changes during conversion:
- Add a fallback for `microchip,sam9x60-can` as it is compatible with the
  CAN IP core on `atmel,at91sam9x5-can`.
- Add the required properties `clock` and `clock-names`, which were
  missing in the original binding.
- 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>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://patch.msgid.link/20241120-can-v3-1-da5bb4f6128d@microchip.com
[mkl: fixed indention in example]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>