laptop-mode-tools: USB autosuspend ignores user input devices

Human input devices (HIDs) like mice and keyboards cannot handle the
auto suspend properly.  This patch modifies the autosuspend script to
check for and ignore all HIDs when enabling auto suspend.

BUG=chromium-os:4534
TEST=verified that HID autosuspend files are not being written to while
non-HID autosuspend files are
Signed-off-by: Simon Que <sque@chromium.org>

Change-Id: If4a881a0efb3177697e1f4b4f15b8171c881f165

Review URL: http://codereview.chromium.org/3590005
2 files changed