CHROMIUM: exynos: dts: de-activate HDMI on Spring

CHROMIUM: exynos: dts: de-activate HDMI on Spring

The board has nothing connected to the HDMI output,
and all sort of badness happen in the HDMI driver during boot since we
have no HDMI PHY.

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
BUG=chrome-os-partner:14489
TEST=boot on Spring and see we no longer have a warning and a backtrace
in hdmiphy_s_power() function or a crash in i2s probing.

Change-Id: I24e384e5ff969ab4c2a25f969bf6d20b94e82ec7
Reviewed-on: https://gerrit.chromium.org/gerrit/35471
Reviewed-by: Olof Johansson <olofj@chromium.org>
Commit-Ready: Vincent Palatin <vpalatin@chromium.org>
Tested-by: Vincent Palatin <vpalatin@chromium.org>