usb: dwc3: turn off VBUS when leaving host mode

BugLink: https://bugs.launchpad.net/bugs/1864774

[ Upstream commit 09ed259f ]

VBUS should be turned off when leaving the host mode.
Set GCTL_PRTCAP to device mode in teardown to de-assert DRVVBUS pin to
turn off VBUS power.

Fixes: 5f94adfe ("usb: dwc3: core: refactor mode initialization to its own function")
Cc: stable@vger.kernel.org
Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

drivers/usb/dwc3/core.c

@@ -801,6 +801,9 @@ static void dwc3_core_exit_mode(struct dwc3 *dwc)
 		/* do nothing */
 		break;
 	}
+
+	/* de-assert DRVVBUS for HOST and OTG mode */
+	dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_DEVICE);
 }
 
 #define DWC3_ALIGN_MASK		(16 - 1)