Set 8259 interrupt vector mappings

        Entry:
          AX = DE0Bh
          BX = first vector used by master 8259
          CX = first vector used by slave 8259
          Interrupts disabled

        Return:
          AH = 00h successful
          AH nonzero: failed

        Notes:  This call merely informs the server that the client has
                changed the interrupt mappings.  The client may not change the
                mappings if they have already been changed by the server or
                another client, and is responsible for restoring the original
                mappings before terminating.