poppy: Adding kernel-doc comments

BUG=chrome-os-partner:61275
BRANCH=None
TEST=None.  No functionality change.

Change-Id: I00bb1924e22f398e1b614789dd0cd068ce51cc5d
Signed-off-by: Shelley Chen <shchen@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/434247
Reviewed-by: Randall Spangler <rspangler@chromium.org>
1 file changed