[NET]: Introduce SIOCGSTAMPNS ioctl to get timestamps with nanosec resolution

Now network timestamps use ktime_t infrastructure, we can add a new
ioctl() SIOCGSTAMPNS command to get timestamps in 'struct timespec'.
User programs can thus access to nanosecond resolution.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
CC: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/compat.h b/include/net/compat.h
index 9859b60..406db24 100644
--- a/include/net/compat.h
+++ b/include/net/compat.h
@@ -25,6 +25,7 @@
 };
 
 extern int compat_sock_get_timestamp(struct sock *, struct timeval __user *);
+extern int compat_sock_get_timestampns(struct sock *, struct timespec __user *);
 
 #else /* defined(CONFIG_COMPAT) */
 #define compat_msghdr	msghdr		/* to avoid compiler warnings */