CONFIG_BF537 is not available for thedefaultarchitecture x86.
Result is shown for architecture blackfin

BF537

configname: CONFIG_BF537

CPU
└─>BF537
In linux kernel since version 2.6.24 (release Date: 2008-01-24)  
BF537 Processor Support.

is selected by
CONFIG_FB_BF537_LQ035