linux-google-veyron: separate from linux-postmarketos-rockchip and upgrade to 6.0

By using shared package we do not share anything between armv7 and aarch64 rockchips, nor patches, neither kernel config. At the same time, it gives a bit of pain, because each change for armv7 chromebooks should be tested on e.g. pinebook pro. Also, testing an aarch64 device does not assume that the same thing will work on armv7. For example, 5.18.0 version has broken USB camera on armv7, but at the same time it works on aarch64. This is why i have decided to separate them

Also, add some patches for HDMI on veyron devices taken from Cadmium project

It is tested on speedy. It is not required to test on minnie and jerry, but it would be appreciated

CC @tvall @nicholas.frillman