Comment 7 for bug 1934489

Ok, turns out it only works on some Intel based laptops. But for them this is still an improvement so I vote for this patch to be keept, as it has no downsides for other devices.

e.g. The Clevo NS50MU Barebone with an i7-1165G7 only outputs 4k@30Hz without this patch, but 4k@60Hz with YCbCr420 with this patch.
Accoring to the spec sheet of the CPU it should be possible to output 4k@60Hz without relying on YCbCr420, but for some reasons this fails. (Didn't check on Windows).

The Clevo L140CU with an i5-10210U cannot output 4k@60Hz with Chroma subsampling.
The spec sheet does not give clear indication whether the CPU supports HDMI 1.4 or 2.0, but it does support 4k@30Hz which should be roughly the same bandwith requirement as 4k@60Hz with chroma subsampling. So i don't know where exactly this fails yet.

TL;DR: Works on Clevo NS50MU, does not work on Clevo L140CU, but also has no negative effect on it -> Patch is still an improvent.