Remove two SPARKFUN_SAMD51_THINGS_PLUS pin definitions. There were
definitions of TXD and RXD, but these pins do not exist on the board. They
were only shown in the schematics.
Also remove any reference to LED_. This is just a text change, no
functional change.
Changes are:
- Remove the LED_Pxxx definitions from pins.csv, now that the LED class is
gone.
- Remove the '-' lines.
- Add default lines for USB and SWCLK, SWDIO.
Instead of being hard-coded, and then it works for all MCUs.
That fits except for a Sparkfun SAMD51 Thing Plus (known) bug, which uses
192k - 4 as magic address. Therefore, that address is set as well to avoid
a problem when this bug is fixed by Sparkfun.
robert-hh