SPI.cpp sets MOSI idle to low

SPI.cpp sets MOSI idle state to low.

This is an error and it makes it incompatible with accepted convention and incompatible with many peripheral chips.

Please comment out the following lines.

https://github.com/arduino/ArduinoCore-renesas/blob/5748045afbe0cabb1fc54bcb60ca6d73f6bcdd84/libraries/SPI/SPI.cpp#L435-L437

If you insist on leaving it like that then at least provide an API so it can be corrected by users.

Open libraries/SPI/SPI.cpp at the linked lines 435-437 and inspect how the MOSI idle state is set. Apply the requested change there, then build or otherwise verify the SPI library; done means MOSI no longer defaults to the reported low idle state.

Written by the indexing model from the issue text.