CONFIG_DEBUG_IMX6Q_UART4 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
default or selected kernelversion does not have config value CONFIG_DEBUG_IMX6Q_UART4.
Result is shown for kernelversion 5.3.7

i.MX6Q Debug UART4

configname: CONFIG_DEBUG_IMX6Q_UART4

Kernel low-level debugging port
└─>i.MX6Q Debug UART4
In linux kernel since version 3.4 (release Date: 2012-05-20)  
Say Y here if you want kernel low-level debugging support
on i.MX6Q UART4.