Change in coreboot[master]: console/flashsconsole: Add spi flash console for debugging

[Youness Alaoui (Code Review)]

Youness Alaoui has posted comments on this change. ( https://review.coreboot.org/19849 )

Change subject: console/flashsconsole: Add spi flash console for debugging
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Patch Set 7:

I've set READ_BUFFER_SIZE to 0x100, and made it return if there's any error reading or writing to the flash. I think it's safer that way. Limiting the I/O is nice, but ultimately, this feature is only for debugging purposes, so it doesn't need to be as optimized as that. It will do 10 reads instead of 1 before stopping, it's not the end of the world.