Change in coreboot[master]: spd: Create new folder for SPD files

[Furquan Shaikh (Code Review)]

Attention is currently required from: Martin Roth, Tim Wawrzynczak, Amanda Hwang, Patrick Rudolph, EricR Lai.
Furquan Shaikh has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/49338 )

Change subject: spd: Create new folder for SPD files
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Patch Set 4:

(1 comment)

File src/mainboard/google/brya/Kconfig:

https://review.coreboot.org/c/coreboot/+/49338/comment/1c01268a_62ade552 
PS4, Line 49: LP4X_SPD_SOURCE_PATH
> One way to eliminate the manual effort for remembering the paths for SPD would be to incorporate tha […]

Once we combine the spd_tools for DDR4 and LP4x, I think we can make the "Path to SPD directory" optional and assume the fixed path ~/coreboot/spd/${MEMORY_TECHNOLOGY}/ since we will need MEMORY_TECHNOLOGY as an input anyways.