Clean up GPIO module.

No functional changes, just code cleanup.

BUG=chrome-os-partner:15579
BRANCH=none
TEST=gpioget returns reasonable values

Change-Id: I4301ccc68ade775f78f4ccd84710d2cd4bc25252
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/36800
5 files changed