CONFIG_SOC_SAMA5D4 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

SAMA5D4 family

modulename: sama5d4.ko

configname: CONFIG_SOC_SAMA5D4

Linux Kernel Configuration
└─>AT91/Microchip SoCs
└─>SAMA5D4 family
In linux kernel since version 3.10 (release Date: 2013-06-30)  
Select this if you are using one of Microchip's SAMA5D4 family SoC.

source code: