CONFIG_BF526 is not available for thedefaultarchitecture x86.
Result is shown for architecture blackfin
default or selected kernelversion does not have config value CONFIG_BF526.
Result is shown for kernelversion 6.7-rc3

BF526

configname: CONFIG_BF526

CPU
└─>BF526
In linux kernel since version 2.6.25 (release Date: 2008-04-16)  
BF526 Processor Support.

is selected by
CONFIG_BFIN_MAC