This replaces the previous make-pin-table.py with an implementation based
on boardgen.py.
- MICROPY_PY_MACHINE_PIN_BOARD_CPU macro is removed. This isn't optional
on other ports, so no need for it to be optional on SAMD.
- pin_af_table is removed, and lookups just search the cpu dict instead
(this saves N*wordsize bytes of firmware size to have this extra table).
- pins.csv is now BOARD,CPU to match other ports.
This work was funded through GitHub Sponsors.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>