netinet/tcp.h: add tcp_zerocopy_receive fields from linux v5.12

see

  linux commit 7eeba1706eba6def15f6cb2fc7b3c3b9a2651edc
  tcp: Add receive timestamp support for receive zerocopy.

  linux commit 3c5a2fd042d0bfac71a2dfb99515723d318df47b
  tcp: Sanitize CMSG flags and reserved args in tcp_zerocopy_receive.

include/netinet/tcp.h

@@ -294,6 +294,10 @@ struct tcp_zerocopy_receive {
 	uint64_t copybuf_address;
 	int32_t copybuf_len;
 	uint32_t flags;
+	uint64_t msg_control;
+	uint64_t msg_controllen;
+	uint32_t msg_flags;
+	uint32_t reserved;
 };
 
 #endif