hle: Add proper type for result code

This should clean up all HLE errorcode in the codebase.

I didn't removed Rust::Result as this should be a cleanup for another
iteration.

include/services/gsp_gpu.hpp

@@ -6,6 +6,7 @@
 #include "kernel_types.hpp"
 #include "logger.hpp"
 #include "memory.hpp"
+#include "result/result.hpp"
 
 enum class GPUInterrupt : u8 {
 	PSC0 = 0, // Memory fill completed