Documentation: timestamping: correct path to net_tstamp.h

net_tstamp.h is an UAPI header, so it was moved under include/uapi.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Documentation/networking/timestamping.txt

@@ -417,7 +417,7 @@ is again deprecated and ts[2] holds a hardware timestamp if set.
 
 Hardware time stamping must also be initialized for each device driver
 that is expected to do hardware time stamping. The parameter is defined in
-/include/linux/net_tstamp.h as:
+include/uapi/linux/net_tstamp.h as:
 
 struct hwtstamp_config {
 	int flags;	/* no flags defined right now, must be zero */
@@ -487,7 +487,7 @@ enum {
 	HWTSTAMP_FILTER_PTP_V1_L4_EVENT,
 
 	/* for the complete list of values, please check
-	 * the include file /include/linux/net_tstamp.h
+	 * the include file include/uapi/linux/net_tstamp.h
 	 */
 };