bash_completion: Add completion for cros command

This adds the initial completion for the cros command.

BUG=none
TEST=cros <tab><tab>
TEST=cros deploy --<tab><tab>
TEST=cros --board=<tab><tab>

Change-Id: Ia29c6500fa1d56d1ce1befcc5257cb8975e26875
Reviewed-on: https://chromium-review.googlesource.com/1893499
Tested-by: Craig Hesling <hesling@chromium.org>
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Legacy-Commit-Queue: Commit Bot <commit-bot@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
1 file changed