VideoCommon: Constrain the array_base registers

The array_base registers as part of CP state do not seem to incorporate
the upper bits in the physical address they try to access.

Source/Core/VideoCommon/CommandProcessor.h

@@ -169,4 +169,6 @@ void SetCpStatusRegister();
 
 void HandleUnknownOpcode(u8 cmd_byte, void* buffer, bool preprocess);
 
+u32 GetPhysicalAddressMask();
+
 }  // namespace CommandProcessor