[Ozone-Dri] Set DPMS to off when disabling a display

[Ozone-Dri] Set DPMS to off when disabling a display

Need to turn it off to reduce the power used by the display when idling.

BUG=chrome-os-partner:35458
TEST=Wait for the displays to turn off and check with 'modetest -c' that the DPMS state is off

Committed: https://crrev.com/46c8606644c297cd5e7271805192d9df5dd698ce
Cr-Commit-Position: refs/heads/master@{#315111}

[dnicoara, 2015-02-06 19:02:50]

dnicoara@chromium.org changed reviewers:
+ spang@chromium.org

[dnicoara, 2015-02-06 19:02:50]

PTAL

[spang, 2015-02-06 20:51:57]

lgtm

[dnicoara, 2015-02-06 21:30:38]

The CQ bit was checked by dnicoara@chromium.org

[commit-bot: I haz the power, 2015-02-06 21:31:14]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/877213005/1

[commit-bot: I haz the power, 2015-02-06 21:34:50]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-06 21:35:29]

Patchset 1 (id:??) landed as
https://crrev.com/46c8606644c297cd5e7271805192d9df5dd698ce
Cr-Commit-Position: refs/heads/master@{#315111}