edid: Add struct and defines for cea681 extension blocks

Add a struct describing the (fixed) bits of cea681 edid extension blocks,
and defines for accessing various bitfields.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
sunxi: video: Add hdmi support

So far we've been programming the hdmi-encoder to send out dvi data over the
hdmi connector. This works well for most devices, including hdmi devices, but
not all devices accept dvi data on a hdmi input.

Add support for sending proper hdmi data over the hdmi output found on most
sunxi boards. This can be turned on by adding by adding monitor=hdmi as option
to the video-mode env. variable.

A follow up patch will determine wether to send dvi or hdmi automatically when
EDID is used.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
sunxi: video: Add sunxi_hdmi_edid_get_block helper function

Add a sunxi_hdmi_edid_get_block helper function, this is a preparation patch
for adding support for parsing EDID extension blocks.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
sunxi: video: When using edid use CEA681 extension blocks to select hdmi output

When using edid use CEA681 edid extension blocks to select between dvi and
hdmi output formats, so that u-boot will automatically do the right thing.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>