futility: updater: Revise getopt_long and use enum instead of chars
futility: updater: Revise getopt_long and use enum instead of chars

For options only available in long-form (--something), we should encode
using enum OPT_SOMETHING instead of random characters.

Also added dummy --update_ec, --update_pd, and --check_keys because
getopt* needs to have them explicitly defined (while the original
shflags will generate both --cmd and --nocmd automatically).

BUG=chromium:943262
TEST=make futil; tests/futility/run_test_scripts.sh $(pwd)/build/futility
BRANCH=None

Change-Id: I701d88f6f5c346581651ed4f8bf004203672e209
Signed-off-by: Hung-Te Lin <8a7fce4940baad93a69f5073b383c85deed9d9c4@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1569145

coreboot/vboot,coreboot/vboot,coreboot/vboot,coreboot/vboot,coreboot/vboot