[1/2] USB: Add support to store lane count used by USB 3.2

USB 3.2 specification adds Dual-lane support, doubling the maximum
SuperSpeedPlus data rate from 10Gbps to 20Gbps.

Dual-lane takes into use a second set of rx and tx wires/pins in the
Type-C cable and connector.

Add a "lanes" variable to struct usb_device to store the numer of lanes
in use. Number of lanes can be read using the extended port status hub
request that was introduced in USB 3.1.

Extended port status rx and tx lane count are zero based, maximum
lanes supported by usb 3.2 is 2 (dual lane).
If extended port status is not available then default to one lane.

Signed-off-by: Mathias Nyman <redacted>
---
 drivers/usb/core/hub.c | 6 ++++++
 include/linux/usb.h    | 2 ++
 2 files changed, 8 insertions(+)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index c5c1f6c..853516d 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c

@@ -2742,6 +2742,12 @@ static int hub_port_wait_reset(struct usb_hub *hub, int port1,
 	if (!udev)
 		return 0;
 
+	if (hub_is_superspeedplus(hub->hdev))
+		udev->lanes = ((ext_portstatus &
+				USB_EXT_PORT_STAT_RX_LANES) >> 8) + 1;