drm/exynos/hdmi: use array specifier for HDMI-PHY configurations

HDMI-PHY configurations are stored as array pointer and count pair,
we can re-use existing helpers to simplify their initialization.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>