CONFIG_DEBUG_SUNXI_UART0 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

Kernel low-level debugging messages via sunXi UART0

configname: CONFIG_DEBUG_SUNXI_UART0

Kernel low-level debugging port
└─>Kernel low-level debugging messages via sunXi UART0
In linux kernel since version 3.1 (release Date: 2011-10-24)  
Say Y here if you want kernel low-level debugging support
on Allwinner A1X based platforms on the UART0.