ARM: exynos: lcd: Remove ptn3460 initialization

ARM: exynos: lcd: Remove ptn3460 initialization

Removes PTN3460 bridge initialization code out of the board setup. We
will use the PTN3460 bridge driver to do this instead.

BUG=chrome-os-partner:10829
BUG=chrome-os-partner:11158
BUG=chrome-os-partner:12046
TEST=Tested on snow, screen came up on power-on and resume

Change-Id: I0bd6e57a2e568efc936ddb3102a0b823fe2c2ae9
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/29345
Reviewed-by: Olof Johansson <olofj@chromium.org>