kernel

Enable use of HDMI 2.0 display modes, e.g. 4K@60Hz, by permitting TMDS
character rates above the 340 MHz limit of HDMI 1.4b.

Hence, add the required support for SCDC management, including the high
TMDS clock ratio and scrambling setup.

Additionally, filter out HDMI 2.1 display modes.

Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>