CONFIG_8260 is not available for the default architecture x86.
Result is shown for architecture powerpc

CONFIG_8260 (not configurable)

configname: CONFIG_8260

Linux Kernel Configuration
└─> 8260

The MPC8260 is a typical embedded CPU made by Freescale. Selecting
this option means that you wish to build a kernel for a machine with
an 8260 class CPU.