drm/sti: add hdmi_mode property for HDMI connector

Configures the framer of the HDMI connection.
By default starts in HDMI mode and can be swtich to DVI.

Signed-off-by: Vincent Abriou <vincent.abriou@st.com>
Reviewed-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
2 files changed