CONFIG_ARCH_SUNXI is not available for thedefaultarchitecture x86.
Result is shown for architecture arm64

Allwinner sunxi 64-bit SoC Family

modulename: sunxi.ko

configname: CONFIG_ARCH_SUNXI

Linux Kernel Configuration
└─>Platform selection
└─>Allwinner sunxi 64-bit SoC Family
In linux kernel since version 3.1 (release Date: 2011-10-24)  
This enables support for Allwinner sunxi based SoCs like the A64.