CONFIG_DEBUG_RK32_UART2 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

Kernel low-level debugging messages via Rockchip RK32 UART2

configname: CONFIG_DEBUG_RK32_UART2

Kernel low-level debugging port
└─>Kernel low-level debugging messages via Rockchip RK32 UART2
In linux kernel since version 3.17 (release Date: 2014-10-05)  
Say Y here if you want kernel low-level debugging support
on Rockchip RK32xx based platforms.