Add reworked HDMI output support

Add reworked support for the Synopsis DesignWare HDMI QP transmitter.

For now, just RGB output up to 4K@30Hz (maybe 4K@60Hz works as well), without audio, CEC or any of the HDMI 2.1 specific features.

This needs some testing on a 4K display as I could only validate up to 2560x1440 @75Hz.