Add functions needed to read the endorsement key. This adds a function for parsing NV_ReadPublic response as well as for serializing and parsing the response of NV_Read commands. BUG=b:354037334 Change-Id: I1ce77eedf4da8dd203a15fb3fc780ce418aa5531 Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/6268244 Tested-by: Johnathan Van Why <[email protected]> Reviewed-by: Jett Rink <[email protected]> Commit-Queue: Johnathan Van Why <[email protected]>