max17055: Put into a hibernation mode at power off
max17055 can be put into a low-power hibernation mode - it automatically sleeps once the current draw becomes low enough. It makes the ADC readings much rarer, so we don't want it to get into that mode when the phone is running, but since max17055 is one of the few things that remains on even when the whole phone is off, we may want to utilize the hibernation mode then and save a few µA.
Currently the max170xx driver doesn't touch hibernation config at all. I think we would like it to wake up the gauge and disable hibernation at init, and allow it to hibernate again when the system shuts down.
See https://pdfserv.maximintegrated.com/en/an/AN6358.pdf - pages 33-35; and https://pdfserv.maximintegrated.com/en/an/MAX17055-software-implementation-guide.pdf - page 4.