Beelink GS1 has a DDC I2C bus voltage shifter. This is actually missing
and video is limited to 1024x768 due to missing EDID information.

Add the DDC regulator in the device-tree.
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>