Adding PRR protection for MRC settings and RO area of Flash

BUG=chromium:1040046
TEST=run in developer and non-developer mode and verify that the right
sections are write protected

Change-Id: Icdeda00bc98d8ba6834490c6a3f0ca86d326a754
Signed-off-by: [email protected]
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/coreboot/+/2039492
Reviewed-by: Furquan Shaikh <[email protected]>
Commit-Queue: Furquan Shaikh <[email protected]>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/coreboot/+/2044929
7 files changed