Convert the Xtensa interrupt controller bindings to DT schema. Both only
vary by the compatible string, so combine them into 1 schema doc.
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Link: https://lore.kernel.org/r/20250505144626.1287879-1-robh@kernel.org
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
