kukui: scp: Make comment for EC_FEATURE_SCP better.
kukui: scp: Make comment for EC_FEATURE_SCP better.

Since SCP is not a feature that EC can "support", change the wording of
the comment to explain better.

BUG=None
BRANCH=None
TEST=None

Change-Id: I77ad7df0235b6e034047831c602c3017647f2870
Signed-off-by: Pi-Hsun Shih <ff63520c4a9bec8f60b967b663461a2165d13bdc@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1560933
Commit-Ready: ChromeOS CL Exonerator Bot <fa429e5907f00867f797423aea74327bb02c91b6@appspot.gserviceaccount.com>

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