IR: Change VAESDec to use IR::OpSize

FEXCore/Source/Interface/IR/IR.json

@@ -2627,7 +2627,7 @@
         "Desc": "Does the last step of AES encryption",
         "DestSize": "RegisterSize"
       },
-      "FPR = VAESDec u8:#RegisterSize, FPR:$State, FPR:$Key, FPR:$ZeroReg": {
+      "FPR = VAESDec OpSize:#RegisterSize, FPR:$State, FPR:$Key, FPR:$ZeroReg": {
         "Desc": "Does a step of AES decryption",
         "DestSize": "RegisterSize"
       },