video: sunxi: Remove check for ddc-i2c-bus property

No Allwinner board with DW-HDMI controller use separate I2C bus for
EDID read. Remove that check.

Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>