CONFIG_M5249 is not available for thedefaultarchitecture x86.
Result is shown for architecture m68k

MCF5249

modulename: m5249.ko

configname: CONFIG_M5249

Linux Kernel Configuration
└─>MCF5249
In linux kernel since version 2.6.12  
Motorola ColdFire 5249 processor support.

source code:
arch/m68k/platform/coldfire/