usb: chipidea: host: fix disconnection detect issue

usb: chipidea: host: fix disconnection detect issue

The commit 4e88d4c08301 ("usb: add a flag to skip PHY
initialization to struct usb_hcd") delete the assignment
for hcd->usb_phy, it causes usb_phy_notify_connect{disconnect)
are not called, the USB PHY driver is not notified of hot plug
event, then the disconnection will not be detected by hardware.

Fixes: 4e88d4c08301 ("usb: add a flag to skip PHY initialization
	to struct usb_hcd")
Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reported-by: Mats Karrman <mats.dev.list@gmail.com>
Tested-by: Mats Karrman <mats.dev.list@gmail.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>