isa_parser: Get rid of the now unused ControlBitfieldOperand.
isa_parser: Get rid of the now unused ControlBitfieldOperand.

andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin