Change in coreboot[master]: soc/amd/common/block/lpc/spi_dma: Implement readat_async

[Raul Rangel (Code Review)]

Attention is currently required from: Jason Glenesk, Marshall Dawson, Felix Held.
Hello build bot (Jenkins), Jason Glenesk, Marshall Dawson, Felix Held,

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/55857

to look at the new patch set (#7).

Change subject: soc/amd/common/block/lpc/spi_dma: Implement readat_async
......................................................................

soc/amd/common/block/lpc/spi_dma: Implement readat_async

This change implements the region_device async readat API. The
implementation is a simple state machine that iterates over a queue
starting new transactions whenever the previous one has completed.

There is a magic bit that needs to be set for the SPI DMA controller to
function correctly. This is only available in RN/CZN+.

BUG=b:179699789
TEST=Boot guybrush to OS

Signed-off-by: Raul E Rangel 
Change-Id: I0be555956581fd82bbe1482d8afa8828c61aaa00
---
M src/soc/amd/common/block/include/amdblocks/lpc.h
M src/soc/amd/common/block/lpc/spi_dma.c
2 files changed, 282 insertions(+), 4 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/57/55857/7