usb: phy: Fix NULL pointer exception during usb_get_phy

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: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/phy/phy-isp1301.c b/drivers/usb/phy/phy-isp1301.c
index 225ae6c..8a55b37 100644
--- a/drivers/usb/phy/phy-isp1301.c
+++ b/drivers/usb/phy/phy-isp1301.c
@@ -102,6 +102,7 @@
 	mutex_init(&isp->mutex);
 
 	phy = &isp->phy;
+	phy->dev = &client->dev;
 	phy->label = DRV_NAME;
 	phy->init = isp1301_phy_init;
 	phy->set_vbus = isp1301_phy_set_vbus;