usb: dwc3: Remove boundary check while traversing the TRB ring buffer

Commit 694dfaa2 ("usb: dwc3: Add boundary check while traversing
the TRB ring buffer") adds a boundary check while traserving the ring
buffer for not iterating past the TRB. Removing this patch as already
upstream patch is there for this.

Change-Id: I1522226cadbd956bf8a9658554b94b4f3f407739
Signed-off-by: Udipto Goswami <ugoswami@codeaurora.org>