add max77705 mfd, led drivers (for starqltechn)

cc @dsankouski

This probably wants squashing, but is presented as a history over Samsung's driver for reference.

It was tested a couple of rebases ago, and in a past life it was on top of dsankouski's branch that allows you to use the phone :) so testing is hard in the current state, but it's an LED driver, I'm sure it'll be fine..

The max77705 is in charge of some other things, namely the usb port and I think haptics? But I'm new here, and those things are much more tricky.