CONFIG_M5249C3 is not available for the selected architecture x86.
Result is shown for architecture m68k

Motorola M5249C3 board support

configname: CONFIG_M5249C3

Linux Kernel Configuration
└─>Motorola M5249C3 board support
In linux kernel since version 2.6.12 )
Support for the Motorola M5249C3 board.
depends
CONFIG_M5249