usb: typec: ucsi: Optimise ucsi_unregister()

There is no need to reset the PPM when the interface is
unregistered. Quietly silencing the notifications and then
unregistering everything is enough. This speeds up
ucsi_unregister() a lot.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Tested-by: Ajay Gupta <ajayg@nvidia.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20191104142435.29960-19-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>