usb: musb: jz4740: Register USB role switch

Register a USB role switch, in order to get notified by the connector
driver when the USB role changes. The notification is then transmitted
to the PHY.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Bin Liu <b-liu@ti.com>
Link: https://lore.kernel.org/r/20200316211136.2274-5-b-liu@ti.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>