usb: pd: Notify USB controller every time Rp changes

Allow USB controller to update its self-powered and bMaxPower
status whenever Rp changes dynamically. The source has a
responsiblity to reset the USB data connection in case Rp changes
to cause the sink to change its status, so make DWC3 driver
re-query for this each time it gets a connect done event.

Change-Id: If3b3ddc353d88599d70580c95175806f14e42096
Signed-off-by: Jack Pham <jackp@codeaurora.org>