vk/graphics_state: Add feedback_loop_input_only

On turnip, there are two cases for feedback loops:

- For feedback loops that involve input attachments, everything works as
  normal in GMEM mode but have to do a workaround in sysmem.
- For feedback loops that may involve any texture, GMEM mode is
  impossible and we have to disable it.

Currently we track this through a special flag on the pipeline, but this
won't be practical in the future. Add a flag to the common renderpass
state struct to patch this info through when using our own renderpass.

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/22301>

src/vulkan/runtime/vk_graphics_state.h

@@ -670,6 +670,9 @@ struct vk_render_pass_state {
     */
    VkPipelineCreateFlags pipeline_flags;
 
+   /* True if any feedback loops only involve input attachments. */
+   bool feedback_loop_input_only;
+
    /** VkPipelineRenderingCreateInfo::colorAttachmentCount */
    uint8_t color_attachment_count;