USB: pd: Notify selfpowered state based on type C current

It is required to notify device as selfpowered and bmaxpower as zero
even for non PD capable devices based on Type C current. Hence notify
as selfpowerer in bmAttributes of configuration descriptor in case of
medium or high Type C current.

Change-Id: Ie552560d93a8195f4c69fdaf6086ef3a52b31d39
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>
Signed-off-by: Jack Pham <jackp@codeaurora.org>