Mbed CLI doesn't correctly handle target detection during `mbed dm update device -D <id> -m DETECT`

See title

```
mbed dm update device -D 01671d2e968c0000000000010010038c -m DETECT -t ARM
[mbed] Auto-installing missing Python modules...
Traceback (most recent call last):
File "D:\Work\smcc-example\mbed-os\tools\device_management.py", line 178, in
main()
File "D:\Work\smcc-example\mbed-os\tools\device_management.py", line 173, in main
}[options.action](options) or 0
File "D:\Work\smcc-example\mbed-os\tools\device_management.py", line 79, in inner
mcus = extract_mcus(MbedExtendedArgs(), options)
File "D:\Work\smcc-example\mbed-os\tools\options.py", line 137, in extract_mcus
args_error(parser, "argument -m/--mcu: {}".format(str(exc)))
File "D:\Work\smcc-example\mbed-os\tools\utils.py", line 319, in args_error
parser.error(message)
AttributeError: 'MbedExtendedArgs' object has no attribute 'error'
[mbed] ERROR: "c:\progra~1\python\python.exe" returned error.
Code: 1
Path: "D:\Work\smcc-example"
Command: "c:\progra~1\python\python.exe -u D:\Work\smcc-example\mbed-os\tools\device_management.py update device -D 01671d2e968c0000000000010010038c --toolchain ARM --mcu DETECT --build .\BUILD\DETECT\ARM"
Tip: You could retry the last command with "-v" flag for verbose output
```

CC @theotherjimmy