Use explicit sizes for lightbar_params fields.

The struct lightbar_params used to communicate lightbar settings between the
AP and the EC uses just "int" for some of its fields. The AP currently uses
32-bit values for "int" in both 64-bit and 32-bit mode, but that's just luck
since C only requires that "int" be at least 16 bits.

This change makes the size explicit.

BUG=none
BRANCH=none
TEST=manual

There should be no visible change.

ectool lightbar params > /tmp/foo
ectool lightbar params /tmp/foo

Change-Id: I4d77c16b3c68e179292b824938d2d012e917ad13
Signed-off-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/176364
Reviewed-by: Yung-chieh Lo <yjlou@chromium.org>