CONFIG_SOC_TMS320C6455 is not available for thedefaultarchitecture x86.
Result is shown for architecture c6x

TMS320C6455

modulename: emif.ko

configname: CONFIG_SOC_TMS320C6455

Linux Kernel Configuration
└─>TMS320C6455
In linux kernel since version 3.1 (release Date: 2011-10-24)  
source code:
arch/c6x/platforms/emif.c