[AArch64] Minor MOVI2R improvement.

Use the ZR for both input arguments in the case the immediate is the maximum immediate value.
This allows it to be aliased to MVN when disassembling.

Source/Core/Common/Arm64Emitter.cpp

@@ -1433,7 +1433,7 @@ void ARM64XEmitter::MOVI2R(ARM64Reg Rd, u64 imm, bool optimize)
 		// Max unsigned value
 		// Set to ~ZR
 		ARM64Reg ZR = Is64Bit(Rd) ? SP : WSP;
-		ORN(Rd, Rd, ZR, ArithOption(ZR, ST_LSL, 0));
+		ORN(Rd, ZR, ZR, ArithOption(ZR, ST_LSL, 0));
 		return;
 	}