CONFIG_SOC_AU1100 is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

CONFIG_SOC_AU1100 (not configurable)

configname: CONFIG_SOC_AU1100

Linux/MIPS Kernel Configuration
└─>SOC_AU1100
In linux kernel since version 2.6.12  

is selected by
CONFIG_SND_AU1X00