usb: pd: Streamline sending hard reset

Handle sending of hard reset directly in usbpd_set_state() rather
than deferring it to the usbpd_sm worker, since all uses of it
will always be from a process context anyway. Consolidate sink
and source handling together.

Change-Id: I61e9f2b8c6b70deef1d59b7162f1c37657a6d1af
Signed-off-by: Jack Pham <jackp@codeaurora.org>