CONFIG_STIH41X_DEBUG_ASC2 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

Use StiH415/416 ASC2 UART for low-level debug

configname: CONFIG_STIH41X_DEBUG_ASC2

Kernel low-level debugging port
└─>Use StiH415/416 ASC2 UART for low-level debug
In linux kernel since version 3.11 (release Date: 2013-09-02)  
Say Y here if you want kernel low-level debugging support
on STiH415/416 based platforms like b2000, which has
default UART wired up to ASC2.

If unsure, say N.