dt-bindings: gpu: Add PowerVR Series5 SGX GPUs

The Imagination PowerVR Series5 "SGX" GPU is part of several SoCs from
multiple vendors. Describe how the SGX GPU is integrated in these SoC,
including register space and interrupts. Clocks, reset, and power domain
information is SoC specific.

Signed-off-by: Andrew Davis <afd@ti.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Message-ID: <20240109171950.31010-3-afd@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>