CONFIG_SOC_AR934X is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

CONFIG_SOC_AR934X (not configurable)

configname: CONFIG_SOC_AR934X

Linux Kernel Configuration
└─>SOC_AR934X
In linux kernel since version 3.1 (release Date: 2011-10-24)  

depends
CONFIG_ATH79