CONFIG_ARC_PROMLIB is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

CONFIG_ARC_PROMLIB (not configurable)

configname: CONFIG_ARC_PROMLIB

Linux/MIPS Kernel Configuration
└─>ARC_PROMLIB
In linux kernel since version 2.6.12  

is depended by
CONFIG_SGI_IP32