km: fix license string and compatible strings

As the ownership is now Hitachi Power Grids, change the license string
and adapt the compatible string in DTS files. For kmeter1.dts we
change it to "keymile,KMETER1" for now, as this is then compliant with
what is submitted to the linux kernel. All other boards don't have
a upstreamed version in linux mainline.

Signed-off-by: Holger Brunck <holger.brunck@hitachi-powergrids.com>
CC: Valentin Longchamp <valentin.longchamp@hitachi-powergrids.com>
CC: Heiko Schocher <hs@denx.de>
CC: Marek Vasut <marex@denx.de>
CC: Tom Rini <trini@konsulko.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

include/configs/socfpga_arria5_secu1.h

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0+ */
 /*
- * Copyright (C) 2017-2020 ABB
+ * Copyright (C) 2017-2020 Hitachi Power Grids
  *
  */
 #ifndef __CONFIG_SOCFPGA_SECU1_H__