Upon initialisation (driver probe) a NULL pointer exception
is triggered. This is due to lack of initialisation of
device field in phy structure, which is used by phy
framework in usb_get_phy().

Fix it by initialising the device field.
Signed-off-by: NRobert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: NKishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>