ARM: multi_v7_defconfig: Enable r8a77470 SoC

Enable recently added r8a77470 (RZ/G1C) SoC.
Signed-off-by: Biju Das <biju.das@bp.renesas.com>
Reviewed-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/configs/multi_v7_defconfig

@@ -90,6 +90,7 @@ CONFIG_ARCH_R8A73A4=y
 CONFIG_ARCH_R8A7740=y
 CONFIG_ARCH_R8A7743=y
 CONFIG_ARCH_R8A7745=y
+CONFIG_ARCH_R8A77470=y
 CONFIG_ARCH_R8A7778=y
 CONFIG_ARCH_R8A7779=y
 CONFIG_ARCH_R8A7790=y