CONFIG_8260 is not available for thedefaultarchitecture x86.
Result is shown for architecture ppc

CPM2 Support

modulename: m8260_setup.ko

configname: CONFIG_8260

Linux/PowerPC Kernel Configuration
└─>Platform options
└─>CPM2 Support
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
The MPC8260 is a typical embedded CPU made by Motorola. Selecting
this option means that you wish to build a kernel for a machine with
an 8260 class CPU.

source code:
depends
CONFIG_6xx

is selected by
CONFIG_PCI_8260

is depended by
CONFIG_8272