i2c issues in 6.18 on R4, but not r4pro (both mt7988 with i2c-mux on i2c2)

[Wolfram Sang]

> > Maybe this option should be enabled by default or when the i2c-mux is
> > selected?
> 
> That's what we were discussing. At least a warning will now get printed
> to the logs when booting suggesting the above solution.

FYI, all the commits leading to this breakage are reverted now. Sorry
for your troubles!