Don't know how to recover SPD from UEFI but Try to read memory part number written on chip and provide that. Look for SPD file with that name if it's already present in coreboot.

The schematics for the platform show Samsung K4A8G165WB-BCRC devices which are (8Gb, 2400Mbps, 512Mx16 DDR4).  The samples of hardware that I have are actually fitted with Micron parts.  

I can’t match what is printed on the top of the Micron devices (two lines of text “0JE75” and “D9ZFW”) to any part numbers on Micron’s website.  Is it some kind of encoded version of the part number or is it just factory and build information?  Looking at the website I would assume that the MT40A512M16JY family would be the equivalent parts.

-Andy.