[S] Change in coreboot[main]: src/ec/intel: read board id one time from EC per stage

[Jérémy Compostella (Code Review)]

Attention is currently required from: Cliff Huang, Jamie Ryu, Wonkyu Kim.

Jérémy Compostella has posted comments on this change by Wonkyu Kim. ( https://review.coreboot.org/c/coreboot/+/87247?usp=email )

Change subject: src/ec/intel: read board id one time from EC per stage
......................................................................

Patch Set 2:

(3 comments)

Commit Message:

https://review.coreboot.org/c/coreboot/+/87247/comment/ca874514_912df7c7?usp... :
PS2, Line 7: src/
remove src/

https://review.coreboot.org/c/coreboot/+/87247/comment/5a816fac_d48a2f57?usp... :
PS2, Line 7: id
ID

File src/ec/intel/board_id.c:

https://review.coreboot.org/c/coreboot/+/87247/comment/7f12debe_b59ced7a?usp... :
PS2, Line 26: if (id == BOARD_ID_UNKNOWN) {
```
if (id != BOARD_ID_UNKNOWN)
    return id;
```