ARM: exynos_defconfig: Enable HDMI support

Many Exynos boards have an HDMI port so enable Exynos DRM HDMI
support.
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Kukjin Kim <kgene@kernel.org>

arch/arm/configs/exynos_defconfig

@@ -130,6 +130,7 @@ CONFIG_REGULATOR_S2MPS11=y
 CONFIG_REGULATOR_S5M8767=y
 CONFIG_REGULATOR_TPS65090=y
 CONFIG_DRM=y
+CONFIG_DRM_EXYNOS_HDMI=y
 CONFIG_DRM_BRIDGE=y
 CONFIG_DRM_PTN3460=y
 CONFIG_DRM_PS8622=y