Merge branch 'i2c-mux/for-next' of https://github.com/peda-r/i2c-mux into i2c/for-4.18

This time around we have mostly trivial changes. However, there are
also a couple of "real" patches improving a few aspects of the
demux-pinctrl behavior and we also actually reset pca954x chips on
probe when we have the ability to do so.