keygeneration: add shellcheck source statements to help linting

BUG=None
TEST=`cros lint` is better
BRANCH=None

Change-Id: Ibd0705fe65717d51aed4b3b590906a5abd36a3ea
Signed-off-by: Mike Frysinger <vapier@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/4849249
Reviewed-by: George Engelbrecht <engeg@google.com>
Commit-Queue: George Engelbrecht <engeg@google.com>
24 files changed