arm64: add Renesas R8A77980 support

Add a configuration option for the R-Car V3H (R8A77980) SoC.

Based on the original (and large) patch by Vladimir Barinov.
Signed-off-by: Vladimir Barinov <vladimir.barinov@cogentembedded.com>
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm64/Kconfig.platforms

@@ -196,6 +196,12 @@ config ARCH_R8A77970
 	help
 	  This enables support for the Renesas R-Car V3M SoC.
 
+config ARCH_R8A77980
+	bool "Renesas R-Car V3H SoC Platform"
+	depends on ARCH_RENESAS
+	help
+	  This enables support for the Renesas R-Car V3H SoC.
+
 config ARCH_R8A77995
 	bool "Renesas R-Car D3 SoC Platform"
 	depends on ARCH_RENESAS