Use internal.h in a similar way to the internal.h in sam3x8e. Also,
move the twi pin definitions from internal.h to i2c.c (as they are only
used there).
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
This can be flashed to e.g. the duet wifi using bossac. It requires a
later version as is currently included in the klipper repo (1.8
vs. 1.2). Comms are currently via UART0 only, USB serial is still TBD
Signed-off-by: Florian Heilmann <Florian.Heilmann@gmx.net>
