CONFIG_MACH_MX53_EVK is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
default or selected kernelversion does not have config value CONFIG_MACH_MX53_EVK.
Result is shown for kernelversion 6.2.5

Support MX53 EVK platforms

modulename: board-mx53_evk.ko

configname: CONFIG_MACH_MX53_EVK

Linux Kernel Configuration
└─>Support MX53 EVK platforms
In linux kernel since version 2.6.38 (release Date: 2011-03-14)  
Include support for MX53 EVK platform. This includes specific
configurations for the board and its peripherals.

source code: