ARM: rmobile: Add support R-Car Generation 3

This adds supporting R-Car Generation 3 (Gen3) as Renesas ARM64 SoC.

Signed-off-by: Hiroyuki Yokoyama <hiroyuki.yokoyama.vx@renesas.com>
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>

arch/arm/mach-rmobile/Kconfig.64

@@ -0,0 +1,12 @@
+if RCAR_GEN3
+
+choice
+	prompt "Renesus ARM64 SoCs board select"
+	optional
+
+endchoice
+
+config SYS_SOC
+	default "rmobile"
+
+endif