ccd: add information about AP flash programming speed up.
ccd: add information about AP flash programming speed up.

When programming AP flash for the very first time it is sufficient to
program just a few sections. This makes it possible for the device to
boot Chrome OS, at which point the rest of the AP flash can be
programmed much faster.

BRANCH=none
BUG=none
TEST=verified proper rendering using gerrit

Change-Id: I444b857302e67c6d7c54c026b9205d0ec734e24a
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1981085
Tested-by: Vadim Bendebury <5515d6d2d0829cbe0dd0dcf2094aaded06d58514@chromium.org>
Reviewed-by: Mary Ruthven <81380f3403fed74252e92df3ed012a1819ec6296@chromium.org>
Commit-Queue: Vadim Bendebury <5515d6d2d0829cbe0dd0dcf2094aaded06d58514@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec