a/vk: move vulkan limits into dedicated vulkan anonymous-struct

Part-of: <https://gitlab.freedesktop.org/monado/monado/-/merge_requests/2639>

src/xrt/auxiliary/vk/vk_bundle_init.c

···
 
 	vk->features.timestamp_compute_and_graphics = pdp.limits.timestampComputeAndGraphics;
 	vk->features.timestamp_period = pdp.limits.timestampPeriod;
-	vk->features.max_per_stage_descriptor_sampled_images = pdp.limits.maxPerStageDescriptorSampledImages;
-	vk->features.max_per_stage_descriptor_storage_images = pdp.limits.maxPerStageDescriptorStorageImages;
+	vk->limits.max_per_stage_descriptor_sampled_images = pdp.limits.maxPerStageDescriptorSampledImages;
+	vk->limits.max_per_stage_descriptor_storage_images = pdp.limits.maxPerStageDescriptorStorageImages;
 
 
 	/*

src/xrt/auxiliary/vk/vk_helpers.h

···
 		//! Were timeline semaphore requested, available, and enabled?
 		bool timeline_semaphore;
 
-		//! Per stage limit on sampled images (includes combined).
-		uint32_t max_per_stage_descriptor_sampled_images;
-
-		//! Per stage limit on storage images.
-		uint32_t max_per_stage_descriptor_storage_images;
-
 		//! Was synchronization2 requested, available, and enabled?
 		bool synchronization_2;
 
···
 		//! Was KHR_video_maintenance1 requested, available, and enabled?
 		bool video_maintenance_1;
 	} features;
+
+	struct
+	{
+		//! Per stage limit on sampled images (includes combined).
+		uint32_t max_per_stage_descriptor_sampled_images;
+
+		//! Per stage limit on storage images.
+		uint32_t max_per_stage_descriptor_storage_images;
+	} limits;
 
 	//! Is the GPU a tegra device.
 	bool is_tegra;

src/xrt/compositor/render/render_resources.c

···
 	r->compute.ubo_binding = 3;
 
 	r->compute.layer.image_array_size =
-	    MIN(vk->features.max_per_stage_descriptor_sampled_images, RENDER_MAX_IMAGES_SIZE);
+	    MIN(vk->limits.max_per_stage_descriptor_sampled_images, RENDER_MAX_IMAGES_SIZE);
 
 
 	/*