CONFIG_ARCH_FOOTBRIDGE is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
FootBridge Implementations
configname: CONFIG_ARCH_FOOTBRIDGE
Linux Kernel Configuration
└─>FootBridge Implementations
In linux kernel since version 2.6.12
Support for systems based on the DC21285 companion chip
("FootBridge"), such as the Simtec CATS and the Rebel NetWinder.
("FootBridge"), such as the Simtec CATS and the Rebel NetWinder.