dt-bindings: gpu: Add 'resets' property for GPU initialization

All IMG Rogue GPUs include a reset line that participates in the
power-up sequence. On some SoCs (e.g., T-Head TH1520 and Banana Pi
BPI-F3), this reset line is exposed and must be driven explicitly to
ensure proper initialization.

To support this, add a 'resets' property to the GPU device tree
bindings.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Michal Wilczynski <m.wilczynski@samsung.com>
Reviewed-by: Matt Coster <matt.coster@imgtec.com>
Link: https://lore.kernel.org/r/20250418-apr_18_reset_img-v6-1-85a06757b698@samsung.com
Signed-off-by: Matt Coster <matt.coster@imgtec.com>

Documentation/devicetree/bindings/gpu/img,powervr-rogue.yaml

@@ -64,6 +64,9 @@ properties:
 
   dma-coherent: true
 
+  resets:
+    maxItems: 1
+
 required:
   - compatible
   - reg