gpu: Note hardware supported by Tier 1 Resource Binding

include/SDL3/SDL_gpu.h

@@ -2263,7 +2263,9 @@ extern SDL_DECLSPEC SDL_GPUDevice * SDLCALL SDL_CreateGPUDevice(
  *   By default, Resourcing Binding Tier 2 is required for D3D12 support.
  *   However, an application can enable this property to enable Tier 1 support,
  *   if (and only if) the application uses 8 or fewer storage resources across
- *   all shader stages.
+ *   all shader stages. As of writing, this property is useful for targeting
+ *   Intel Haswell and Broadwell GPUs; other hardware either supports Tier 2
+ *   Resource Binding or does not support D3D12 in any capacity.
  *
  * With the Vulkan renderer:
  *