arm64: defconfig: enable R8A774A1 SoC

Enable the Renesas RZ/G2M (R8A774A1) SoC in the ARM64 defconfig.
Signed-off-by: Biju Das <biju.das@bp.renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm64/configs/defconfig

@@ -49,6 +49,7 @@ CONFIG_ARCH_ROCKCHIP=y
 CONFIG_ARCH_SEATTLE=y
 CONFIG_ARCH_SYNQUACER=y
 CONFIG_ARCH_RENESAS=y
+CONFIG_ARCH_R8A774A1=y
 CONFIG_ARCH_R8A7795=y
 CONFIG_ARCH_R8A7796=y
 CONFIG_ARCH_R8A77965=y