drm/exynos/hdmi: remove support for deprecated compatible

This compatible was marked as deprecated in Jun 2013 and it is not used since
then. Additionally its driver data points to wrong pll settings, so it
cannot work anyway.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Reviewed-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>