vulkan: Remove unnecessary includes

Reduces some header churn and reduces rebuilds when some header
internals change.

While we're at it we can also resolve a missing include in buffer_cache.

src/video_core/renderer_vulkan/vk_descriptor_pool.h

@@ -4,10 +4,8 @@
 
 #pragma once
 
-#include <memory>
 #include <vector>
 
-#include "common/common_types.h"
 #include "video_core/renderer_vulkan/vk_resource_manager.h"
 #include "video_core/renderer_vulkan/wrapper.h"