soc/intel/common: remove nvm headers and c file

There's no sense in having the nvm abstraction in its own files. Put
that support directly into mrc_cache.c.

BUG=b:69614064

Change-Id: I0f1a801c6e1a8c35f70faf9e4318bdc45955047a
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/22883
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
4 files changed