include: Update dimm_info documentation

Reference the JEDEC SPD spec and clarify some comments.

BRANCH=dimm-info
BUG=b:65403853
TEST=Documentation change only

Signed-off-by: Raul E Rangel <rrangel@chromium.org>
Change-Id: I1f2a3a70919c34f17472904323ec5accdfc876be
Reviewed-on: https://review.coreboot.org/25301
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
1 file changed