We can get quite a few interrupts when the battery is trickle charging.
Let's enable PM runtime autosuspend to avoid constantly toggling device
driver PM runtime state.

Let's use a 600 ms timeout as that's how long the USB chager detection
might take.
Acked-by: Mark Greer <mgreer@animalcreek.com>
Acked-by: Liam Breck <kernel@networkimprov.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>