CHROMIUM: video: exynos: move dp configuration to a workqueue

CHROMIUM: video: exynos: move dp configuration to a workqueue

This speeds up boot significantly, since it can take up to a second to
get the display up and going, and we want to keep on booting (through
some userspace) while that happens.

BUG=chrome-os-partner:11403
TEST=boot

Change-Id: I88a287d427b870c0521aa0c9aec79fd6d943233e
Signed-off-by: Olof Johansson <olof@lixom.net>
Reviewed-on: https://gerrit.chromium.org/gerrit/28918
Reviewed-by: Olof Johansson <olofj@chromium.org>
Tested-by: Olof Johansson <olofj@chromium.org>
Commit-Ready: Olof Johansson <olofj@chromium.org>