usb: dwc2: fix call to vbus supply exit routine, call it unlocked

dwc2_vbus_supply_exit() may call regulator_disable(). It shouldn't be
called with interrupts disabled as it might sleep.
This is seen with DEBUG_ATOMIC_SLEEP=y.

Fixes: 531ef5ebea96 ("usb: dwc2: add support for host mode external
vbus supply")

Tested-by: Artur Petrosyan <arturp@synopsys.com>
Acked-by: Minas Harutyunyan <hminas@synopsys.com>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc2/hcd.c

@@ -4481,7 +4481,9 @@ static int _dwc2_hcd_suspend(struct usb_hcd *hcd)
 		hprt0 |= HPRT0_SUSP;
 		hprt0 &= ~HPRT0_PWR;
 		dwc2_writel(hsotg, hprt0, HPRT0);
+		spin_unlock_irqrestore(&hsotg->lock, flags);
 		dwc2_vbus_supply_exit(hsotg);
+		spin_lock_irqsave(&hsotg->lock, flags);
 	}
 
 	/* Enter partial_power_down */