arm64: defconfig: enable R8A77970 SoC

Enable the Renesas R-Car V3M (R8A77970) SoC in the ARM64 defconfig.
Suggested-by: NSimon Horman <horms@verge.net.au>
Signed-off-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Acked-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>

arch/arm64/configs/defconfig

@@ -51,6 +51,7 @@ CONFIG_ARCH_SEATTLE=y
 CONFIG_ARCH_RENESAS=y
 CONFIG_ARCH_R8A7795=y
 CONFIG_ARCH_R8A7796=y
+CONFIG_ARCH_R8A77970=y
 CONFIG_ARCH_R8A77995=y
 CONFIG_ARCH_STRATIX10=y
 CONFIG_ARCH_TEGRA=y