[S] Change in coreboot[master]: soc/amd/[glinda|morgana]: Enable override of MAINBOARD_BLOBS_DIR

[Fred Reitberger (Code Review)]

Attention is currently required from: Jason Glenesk, Matt DeVillier, Felix Held.

Fred Reitberger has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/69410 )

Change subject: soc/amd/[glinda|morgana]: Enable override of MAINBOARD_BLOBS_DIR
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Patch Set 1:

(1 comment)

File src/soc/amd/glinda/Makefile.inc:

https://review.coreboot.org/c/coreboot/+/69410/comment/2cd3f0af_925a366d 
PS1, Line 61: MAINBOARD_BLOBS_DIR:=$
> we already do this for MDN which is fine, but it seems a little odd to me that we define the MAINBOA […]

Good idea - looks like I could move it from SoC-specific Makefile to the amd common makefile.

However, I'm starting to wonder if it would make more sense to just change this to a Kconfig option with a default "3rdparty/blobs/mainboard/$(MAINBOARDDIR)" and let users/config override it for site-local or other locations?