[coreboot] amd_blobs submodule update issue when using git sup alias and how to fix it

[Felix Held]

Hi!

Quick heads-up: In [1] I updated the submodule pointer of amd_blobs so 
that it now tracks the new official repository [2]. Since the new 
repository and the old don't have common ancestors, using the git sup 
alias to update the submodules, that rebases the changes, will fail 
causing git to fall back to a 3 way merge. Since the new repository 
contains updated firmware blobs, that merge also fails.
To fix the issue run the following commands:
(cd 3rdparty/amd_blobs; git rebase --abort); git submodule update --checkout

Regards
Felix

[1] https://review.coreboot.org/c/coreboot/+/46594/
[2] https://github.com/amd/firmware_binaries