Found a typo in trinamic.c

[rcKeith]

Hi
I was struggling to get the XYZA to show up in ioSender as the screenshot shows
I know I could just set it via the interface but I will be offering the firmware as a free download to the CNC foam-cutting community and I'm sure I would get some users who would struggle. So the aim is to make all the defaults in the eeprom.

and after a few hours of head scratching and searching the code I found at line 424 in trinamic.c
trinamic.driver_enable.z = TMC_A_ENABLE;
changed it to
trinamic.driver_enable.a = TMC_A_ENABLE;

All working fine now, thanks for a great library. This going to power a 4-axis foam cutter using the SKR Pico. I had great success with the grbl Mega 5X but it is time to move on now. Should have some videos out soon.
Keith