INT 21 - DOS 5.0 - IOCTL - QUERY GENERIC IOCTL CAPABILITY (HANDLE)
        AX = 4410h
        BX = handle for device
        CH = category code (see AX=440Ch)
        CL = function code
Return: CF clear if successful
            AX = 0000h  specified IOCTL function is supported
        CF set on error
            AL = 01h    IOCTL capability not available
Note:   a program which wishes to use Generic IOCTL calls beyond those in the
          standard DOS 3.2 set may use this call first to see whether a
          particular call is supported
SeeAlso: AX=440Dh,AX=4411h