Change GetStatePtr() Return to const

Source/Core/Core/PowerPC/PowerPC.cpp

@@ -225,7 +225,7 @@ CPUState GetState()
 	return state;
 }
 
-volatile CPUState *GetStatePtr()
+const volatile CPUState *GetStatePtr()
 {
 	return &state;
 }

Source/Core/Core/PowerPC/PowerPC.h

@@ -160,7 +160,7 @@ void Pause();
 void Stop();
 void FinishStateMove();
 CPUState GetState();
-volatile CPUState *GetStatePtr();  // this oddity is here instead of an extern declaration to easily be able to find all direct accesses throughout the code.
+const volatile CPUState *GetStatePtr();  // this oddity is here instead of an extern declaration to easily be able to find all direct accesses throughout the code.
 
 u32 CompactCR();
 void ExpandCR(u32 cr);