Add SPI Flash chip

[BlackstoneEngineering]

Suggestion

Add SPI Flash chip to CI Test shiled

Reason

Most deployments will use SPI Flash, not SD Cards. It makes sense to add a SPI Flash chip to the next version of the CI Test shield.

Implementation

Add 16MB SPI Flash chip to board, add CS Line to... not D0/D1.

[BlackstoneEngineering]

@chris-styles @andcor02 - based on conversation with Chris. May be too late to implement in 2.0.x design, may wait till next major rev to implement, but should be added in future.

[bridadan]

To avoid the flash wearing out, you might also consider using volatile storage, something closer to a RAM chip. Though this may have complications depending on the different test scenarios you have.