libiosuhax: Use wiiu headers instead of redefining

deps/libiosuhax/os_functions.h

@@ -6,6 +6,11 @@ extern "C" {
 #endif
 
 #define OS_MUTEX_SIZE                   44
+
+// RetroArch mod: use existing headers; prevents conflicts in griffin
+#include <wiiu/os.h>
+#include <wiiu/ios.h>
+#if 0
 
 #ifndef __WUT__
 //!----------------------------------------------------------------------------------------------------------------------------------------------------------------------------
@@ -41,4 +46,6 @@ extern int IOS_Close(int fd);
 }
 #endif
 
+#endif // 0
+
 #endif // __OS_FUNCTIONS_H_