usb: tps6598x: Export some power supply properties
A quick hack to make charging detection work
I've used a supply name that's already known by our upower but I'll extend upower as well after some more testing. I'll also add more properties so we can detect more usb-c properties from userspace.
Closes: OS-issues#90
Signed-off-by: Guido Günther guido.gunther@puri.sm