dt-bindings: interrupt-controller: Convert ARM VIC to json-schema

Convert the ARM VIC binding document to DT schema format using
json-schema.

Cc: Rob Herring <robh@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20210617205317.3060163-1-sudeep.holla@arm.com


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