CONFIG_MACH_SAMA5_DT is not available for the selected architecture x86.
Result is shown for architecture arm
Atmel SAMA5 Evaluation Kits with device-tree support
modulename: board-dt-sama5.ko
configname: CONFIG_MACH_SAMA5_DT
Linux Kernel Configuration
└─>Atmel AT91 System-on-Chip
└─>Atmel SAMA5 Evaluation Kits with device-tree support
In linux kernel since version 3.1 (release Date: 2011-10-24)
Select this if you want to experiment device-tree with
an Atmel Evaluation Kit.
an Atmel Evaluation Kit.