M122 add actual and max current measured by TMC

[pipersw]

Hi,
With Marlin and TMC2208, if I send M122 gcode, it show the actual current used by each steppers (http://marlinfw.org/docs/gcode/M122.html](http://marlinfw.org/docs/gcode/M122.html).

it's possible to add in DWC the followings output with M122:

                  X     Y    Z   E0 
Set current       850   850  850 800
Run current       826   826  400 800
MAX current       1165  1165 600 900
Hold current      500   500  500 500