codec: Add missing <string_view> include

src/video_core/command_classes/codecs/codec.h

@@ -5,6 +5,7 @@
 #pragma once
 
 #include <memory>
+#include <string_view>
 #include <queue>
 #include "common/common_types.h"
 #include "video_core/command_classes/nvdec_common.h"