CONFIG_DEBUG_OMAP4UART4 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

Kernel low-level debugging messages via OMAP4/5 UART4

configname: CONFIG_DEBUG_OMAP4UART4

Kernel low-level debugging port
└─>Kernel low-level debugging messages via OMAP4/5 UART4
In linux kernel since version 3.1 (release Date: 2011-10-24)