xhci: Rate-limit XHCI_TRUST_TX_LENGTH quirk warning.

When we encounter an xHCI host that needs the XHCI_TRUST_TX_LENGTH
quirk, the xHCI driver ends up spewing messages about the quirk into
dmesg every time a short packet occurs.  Change the xHCI driver to
rate-limit such warnings.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Reported-by: Matthew Hall <mhall@mhcomputing.net>
Reported-by: Gary E. Miller <gem@rellim.com>
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 55c0785..96f49db 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1537,6 +1537,8 @@
 	dev_err(xhci_to_hcd(xhci)->self.controller , fmt , ## args)
 #define xhci_warn(xhci, fmt, args...) \
 	dev_warn(xhci_to_hcd(xhci)->self.controller , fmt , ## args)
+#define xhci_warn_ratelimited(xhci, fmt, args...) \
+	dev_warn_ratelimited(xhci_to_hcd(xhci)->self.controller , fmt , ## args)
 
 /* TODO: copied from ehci.h - can be refactored? */
 /* xHCI spec says all registers are little endian */