tlsdated: Wait until /dev/rtc comes up in upstart

ChromeOS devices should have hwclocks, so wait for a few seconds to
make sure tlsdated and bootstat can use the hwclock device.

BUG=b:320904897
TEST=Pass 100 BootPerf cycles on asurada-kernelnext

Change-Id: Icde2d099ed4fb1a39023d06f217bbd2b2bcfc569
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/tlsdate/+/5315242
Tested-by: Pin-yen Lin <treapking@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Pin-yen Lin <treapking@chromium.org>
Reviewed-by: Hugo Benichi <hugobenichi@google.com>
Reviewed-by: Brian Norris <briannorris@chromium.org>
1 file changed