CONFIG_ARCH_FOOTBRIDGE is not available for the selected architecture 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.