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

Sibyte BCM91250PT-PTSWARM

configname: CONFIG_SIBYTE_PTSWARM

System type
└─>Sibyte BCM91250PT-PTSWARM
In linux kernel since version 2.6.12  

depends
CONFIG_EXPERIMENTAL