There was an empty udelay() implementation result in 0 waits.
Provide an actual implementation.
BUG=None
BRANCH=None
TEST=Built and ran through to depthcharge on rush.
Change-Id: I201f2fdc4e4f5c88d48e4002839b03e808a5a1bc
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/210827
Reviewed-by: Furquan Shaikh <furquan@chromium.org>