ARM: dts: r8a7740, emev2, sh73a0: Include SoC name in DTSI

Update the R-Mobile A1 (r8a7740), Emma Mobile EV2 (emev2) and
SH-Mobile AG5 (sh72a0) DTSI to include product name.
Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
[simon: squashed similar patches]
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/emev2.dtsi

 // SPDX-License-Identifier: GPL-2.0
 /*
- * Device Tree Source for the EMEV2 SoC
+ * Device Tree Source for the Emma Mobile EV2 SoC
  *
  * Copyright (C) 2012 Renesas Solutions Corp.
  */

arch/arm/boot/dts/r8a7740.dtsi

 // SPDX-License-Identifier: GPL-2.0
 /*
- * Device Tree Source for the r8a7740 SoC
+ * Device Tree Source for the R-Mobile A1 (R8A77400) SoC
  *
  * Copyright (C) 2012 Renesas Solutions Corp.
  */

arch/arm/boot/dts/sh73a0.dtsi

 // SPDX-License-Identifier: GPL-2.0
 /*
- * Device Tree Source for the SH73A0 SoC
+ * Device Tree Source for the SH-Mobile AG5 (R8A73A00/SH73A0) SoC
  *
  * Copyright (C) 2012 Renesas Solutions Corp.
  */