Change in flashrom[master]: bitbang-spi.c: support clock polarity and phase

[Nico Huber (Code Review)]

Attention is currently required from: Xiang W, Edward O'Callaghan, Angel Pons.
Nico Huber has posted comments on this change. ( https://review.coreboot.org/c/flashrom/+/49255 )

Change subject: bitbang-spi.c: support clock polarity and phase
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Patch Set 26:

(1 comment)

File bitbang_spi.c:

https://review.coreboot.org/c/flashrom/+/49255/comment/93f32fe3_53aa1fb6 
PS26, Line 121: 			programmer_delay(master->half_period);
              : 			bitbang_spi_set_sck_set_mosi(master, !cpol, (val >> i) & 1);
              : 			programmer_delay(master->half_period);
              : 			bitbang_spi_set_sck(master, cpol);
This does not look right and is probably what led to the follow up commit.
With cpha=0, the receiver is supposed to sample the data at the first edge.
So the sequence should be:

* set mosi
* delay
* first edge
* delay
* second edge
* (followed without delay by the next mosi setting)