dt-bindings: fsi: ast2600-fsi-master: Convert to json-schema

Convert to json-schema for the AST2600 FSI master documentation.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240522192524.3286237-9-eajames@linux.ibm.com


Signed-off-by: Rob Herring (Arm) <robh@kernel.org>