usb: dwc3: fix Clear Stall EP command failure

Commit 50c763f8 ("usb: dwc3: Set the ClearPendIN bit on Clear
Stall EP command") sets ClearPendIN bit for all IN endpoints of
v2.60a+ cores. This causes ClearStall command fails on 2.60+ cores
operating in HighSpeed mode.

In page 539 of 2.60a specification:

"When issuing Clear Stall command for IN endpoints in SuperSpeed
mode, the software must set the "ClearPendIN" bit to '1' to
clear any pending IN transcations, so that the device does not
expect any ACK TP from the host for the data sent earlier."

It's obvious that we only need to apply this rule to those IN
endpoints that currently operating in SuperSpeed mode.

Fixes: 50c763f8 ("usb: dwc3: Set the ClearPendIN bit on Clear Stall EP command")
Cc: <stable@vger.kernel.org> # v4.7+
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>