CONFIG_CPU_SB1_PASS_2_1250 is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

1250 An

configname: CONFIG_CPU_SB1_PASS_2_1250

SiByte SOC Stepping
└─>1250 An
In linux kernel since version 2.6.12  
Also called BCM1250 Pass 2