usb: pd: Don't retry sending Source Capabilities if PD capable

If connected to a sink that we already know is PD capable, the
next time Source Capabilities is sent, whether due to reset or
in response Get_Source_Capabilities, upon failure should not
retry for nCapsCount times. Instead, simply issue a Soft Reset.

Change-Id: Ia45600f013555814c008edf60e0daf599d9f9dee
Signed-off-by: Pratham Pratap <prathampratap@codeaurora.org>