usb: cdnsp: do not disable slot for disabled slot

It doesn't need to do it, and the related command event returns
'Slot Not Enabled Error' status.

Fixes: 3d82904 ("usb: cdnsp: cdns3 Add main part of Cadence USBSSP DRD Driver")
Cc: stable <stable@kernel.org>
Suggested-by: Hongliang Yang <hongliang.yang@cixtech.com>
Reviewed-by: Fugang Duan <fugang.duan@cixtech.com>
Signed-off-by: Peter Chen <peter.chen@cixtech.com>
Link: https://lore.kernel.org/r/20250619013413.35817-1-peter.chen@cixtech.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Peter Chen

drivers/usb/cdns3/cdnsp-ring.c

@@ -772,7 +772,9 @@ static int cdnsp_update_port_id(struct cdnsp_device *pdev, u32 port_id)
 	}
 
 	if (port_id != old_port) {
-		cdnsp_disable_slot(pdev);
+		if (pdev->slot_id)
+			cdnsp_disable_slot(pdev);
+
 		pdev->active_port = port;
 		cdnsp_enable_slot(pdev);
 	}