usb: dwc3: shutdown usb_phy when removing the device

We call usb_phy_init() from dwc3_core_init() during
probe, so adding usb_phy_shutdown() to dwc3_core_exit()
while removing the device so we don't keep PHYs
turned on, consuming power, unnecessarily.

Signed-off-by: Vivek Gautam <[e-mail]>
Signed-off-by: Felipe Balbi <[e-mail]>

drivers/usb/dwc3/core.c

···
 {
 	dwc3_event_buffers_cleanup(dwc);
 	dwc3_free_event_buffers(dwc);
+
+	usb_phy_shutdown(dwc->usb2_phy);
+	usb_phy_shutdown(dwc->usb3_phy);
+
 }
 
 #define DWC3_ALIGN_MASK		(16 - 1)