dt-bindings: arm: Convert CSR SiRF board/soc bindings to json-schema

Convert CSR SiRF SoC bindings to DT schema format using json-schema.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Barry Song <baohua@kernel.org>
Cc: devicetree@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Rob Herring <robh@kernel.org>