CONFIG_COBRA5272 is not available for thedefaultarchitecture x86.
Result is shown for architecture m68k

senTec COBRA5272 board support

configname: CONFIG_COBRA5272

Linux Kernel Configuration
└─>senTec COBRA5272 board support
In linux kernel since version 2.6.12  
Support for the senTec COBRA5272 board.

selects
CONFIG_senTec

depends
CONFIG_M5272