CONFIG_MIPS_MTX1 is not available for the selected architecture x86.
Result is shown for architecture mips

4G Systems MTX-1 board

modulename: board-mtx1.ko

configname: CONFIG_MIPS_MTX1

Machine type
└─>4G Systems MTX-1 board
In linux kernel since version 2.6.12 )
source code:
arch/mips/alchemy/board-mtx1.c