Merge CH546 support from drizzt

[jnweiger]

No description provided.

[Sandr0x00]

I added a PR to fix exactly this issue to a forked repo (fossasia#12) which seems to be also containing all further improvements in this PR. Maybe this helps fixing the issue also on this repo by cherry picking, if you don't want the other improvements?
Be aware, I did not test the fix with other devices other than my own CH546, so I'm not aware if my fix breaks other devices.

[jnweiger]

I have lost overview here. Cannot estimate, how much energy is needed to resolve git conflicts.
fossasia seems to be cleanly ahead by 16 commits - if git allows a clean merge back from there, then I am probably happy with that too.

[Sandr0x00]

clean merge should be possible from there (except my PR is not yet merged, so the fix is not yet in there), on the other side, I can also prepare a PR for your repo only containing the fix for CH546. But as previously said, "works with my machine" and I have no way of verifying if it works with others :)
But since multiple people have the issue, it may be worth it