Make sure to disable/enable the peripheral to ensure the clock
polarity is properly set prior to a change in CS.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
This implements SPI for the rp2040 target. All output groupings of both
SPI blocks are available for use.
Signed-off-by: Lasse Dalegaard <dalegaard@gmail.com>