[S] Change in coreboot[main]: payloads/depthcharge: support depthcharge build with local changes

[Cliff Huang (Code Review)]

Attention is currently required from: Anil Kumar K, Bora Guvendik, Jamie Ryu, Martin L Roth.

Hello Anil Kumar K, Bora Guvendik, Jamie Ryu, Martin L Roth, Wonkyu Kim, build bot (Jenkins),

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

https://review.coreboot.org/c/coreboot/+/83225?usp=email

to look at the new patch set (#3).

Change subject: payloads/depthcharge: support depthcharge build with local changes
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payloads/depthcharge: support depthcharge build with local changes

Allow building with local changes.
Add dependency and target for generated static_fw_config.h.
This ensures this file is generated prior to building depthcharge.
Fix 'git fetch' for the repo other than origin/main. It only fetches
latest code if the branch name is origin/main. Use $(DEPTHCHARGE_BRANCH)
to fetch when different branch is used.

TEST=depthcharge should build with local changes

Signed-off-by: Cliff Huang 
Change-Id: I95c1f71ae149537a2191734a62f416b7b6f41fc6
---
M Makefile.mk
M payloads/external/Makefile.mk
M payloads/external/depthcharge/Makefile
3 files changed, 15 insertions(+), 7 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/25/83225/3