Need a way to create an SPI device without a chip select pin

[deanm1278]

e.g. spi_device = SPIDevice(busio.SPI(board.SCK, board.MOSI, board.MISO), None, baudrate=4000000)

This is for things like displays that have other signals to be managed during a transaction. We want to tell the busDevice to not worry about chip select, we will manage it ourselves manually.

[cerickson]

I'll work on this one.