If the disassembler is configured out (such as when the debugger
is part of a kernel), these debugger commands are disabled:
    List
    Disassemble
Further, the Debug (single-step) command is simplified because
each line of code cannot be disassembled.
Reported-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NBob Moore <robert.moore@intel.com>
Signed-off-by: NErik Schmauss <erik.schmauss@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>