util/ectool: Update usages for cros_scp.
util/ectool: Update usages for cros_scp.

cros_scp uses cros_ec_dev kernel driver, additional implementation
is not needed.

TEST=use "ectool --name=cros_scp version" in AP console, and see the
     version info.
BRANCH=None
BUG=b:114326670

Change-Id: Ie01fc4e3463d42daecf3c02302f8863aabfaa7da
Signed-off-by: Yilun Lin <2f2733c7206ea2b76bd2db1905cc5e8a75841c48@google.com>
Reviewed-on: https://chromium-review.googlesource.com/1424044
Commit-Ready: Nicolas Boichat <f3daba1cdc403799935674d3cd4b0e5bd1804232@chromium.org>
Tested-by: Yilun Lin <2f2733c7206ea2b76bd2db1905cc5e8a75841c48@chromium.org>
Reviewed-by: Nicolas Boichat <f3daba1cdc403799935674d3cd4b0e5bd1804232@chromium.org>

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