net: update NXP copyright text

NXP Legal insists that the following are not fine:

- Saying "NXP Semiconductors" instead of "NXP", since the company's
  registered name is "NXP"

- Putting a "(c)" sign in the copyright string

- Putting a comma in the copyright string

The only accepted copyright string format is "Copyright <year-range> NXP".

This patch changes the copyright headers in the networking files that
were sent by me, or derived from code sent by me.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
diff --git a/include/configs/ls1021atsn.h b/include/configs/ls1021atsn.h
index 58c2d97..0dd891b 100644
--- a/include/configs/ls1021atsn.h
+++ b/include/configs/ls1021atsn.h
@@ -1,5 +1,5 @@
 /* SPDX-License-Identifier: GPL-2.0
- * Copyright 2016-2019 NXP Semiconductors
+ * Copyright 2016-2019 NXP
  * Copyright 2019 Vladimir Oltean <olteanv@gmail.com>
  */