Change in coreboot[master]: soc/amd/cezanne/romstage: Preload fspm.bin

[Raul Rangel (Code Review)]

Attention is currently required from: Jason Glenesk, Marshall Dawson, Felix Held.
Hello Jason Glenesk, Marshall Dawson, Felix Held,

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

https://review.coreboot.org/c/coreboot/+/58988

to look at the new patch set (#2).

Change subject: soc/amd/cezanne/romstage: Preload fspm.bin
......................................................................

soc/amd/cezanne/romstage: Preload fspm.bin

FSP-M is normally memmapped and then decompressed. The SPI DMA
controller can actually read faster than mmap. So by reading the
contents into a buffer and then decompressing we reduce boot time.

BUG=b:179699789
TEST=Boot guybrush and see 30ms reduction in boot time
| 970 - loading FSP-M                                 | 0.31      | 0.992     Δ(  0.68,    0.04%) |
| 15 - starting LZMA decompress (ignore for x86)      | 0.024     | 9.472     Δ(  9.45,    0.62%) |
| 16 - finished LZMA decompress (ignore for x86)      | 54.011    | 11.05     Δ(-42.96,   -2.82%) |

Signed-off-by: Raul E Rangel 
Change-Id: I850b1576501753a355e7b23745e04802a0560387
---
M src/soc/amd/cezanne/Kconfig
M src/soc/amd/cezanne/romstage.c
2 files changed, 10 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/88/58988/2