CHROMIUM: exynos5: add support for LCD on Spring

CHROMIUM: exynos5: add support for LCD on Spring

Allow to configure DP output for either NXP or Parade eDP-LVDS bridge.
Set sensible LCD panel settings for Spring.

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
BUG=chrome-os-partner:14491
TEST=run on Spring and Snow and see display coming up on ChromeOS
startup on both machines.

Change-Id: I3cd46327a9d8fd6010c8d308111c6c0267fedae4
Reviewed-on: https://gerrit.chromium.org/gerrit/36233
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Commit-Ready: Vincent Palatin <vpalatin@chromium.org>
Tested-by: Vincent Palatin <vpalatin@chromium.org>