usb: chipidea: add PTW, PTS and STS handling

This patch makes it possible to configure the PTW, PTS and STS bits
inside the portsc register for host and device mode before the driver
starts and the phy can be addressed as hardware implementation is
designed.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>