drm/exynos: hdmi: consider APB PHY

This patch returns error in case of using APB PHY.

Exynos5420 SoC and maybe later would use APB PHY instead of
I2C PHY so such case should be considered.

Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>