CONFIG_BF536 is not available for thedefaultarchitecture x86.
Result is shown for architecture blackfin

BF536

configname: CONFIG_BF536

CPU
└─>BF536
In linux kernel since version 2.6.24 (release Date: 2008-01-24)  
BF536 Processor Support.

is selected by
CONFIG_FB_BF537_LQ035