mwifiex: change license text of Makefile and README from MARVELL to NXP

As of 6-DEC-2019, NXP has acquired Marvell’s Wireless business
unit. This change is to update the license text accordingly.

commit 932183aa ("mwifiex: change license text from MARVELL
to NXP") does this, but it left out two files.
Signed-off-by: NJames Cao <zheng.cao@nxp.com>
Signed-off-by: NCathy Luo <xiaohua.luo@nxp.com>
Signed-off-by: NGanapathi Bhat <ganapathi.bhat@nxp.com>
Signed-off-by: NKalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1606814307-32715-1-git-send-email-ganapathi.bhat@nxp.com

drivers/net/wireless/marvell/mwifiex/Makefile

 #
-# Copyright (C) 2011-2014, Marvell International Ltd.
+# Copyright 2011-2020 NXP
 #
-# This software file (the "File") is distributed by Marvell International
-# Ltd. under the terms of the GNU General Public License Version 2, June 1991
+# This software file (the "File") is distributed by NXP
+# under the terms of the GNU General Public License Version 2, June 1991
 # (the "License").  You may use, redistribute and/or modify this File in
 # accordance with the terms and conditions of the License, a copy of which
 # is available by writing to the Free Software Foundation, Inc.,

drivers/net/wireless/marvell/mwifiex/README

-# Copyright (C) 2011-2014, Marvell International Ltd.
 #
-# This software file (the "File") is distributed by Marvell International
-# Ltd. under the terms of the GNU General Public License Version 2, June 1991
+# Copyright 2011-2020 NXP
+#
+# This software file (the "File") is distributed by NXP
+# under the terms of the GNU General Public License Version 2, June 1991
 # (the "License").  You may use, redistribute and/or modify this File in
 # accordance with the terms and conditions of the License, a copy of which
 # is available by writing to the Free Software Foundation, Inc.,