CONFIG_ARCH_MX53_SUPPORTED is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

CONFIG_ARCH_MX53_SUPPORTED (not configurable)

configname: CONFIG_ARCH_MX53_SUPPORTED

Linux Kernel Configuration
└─>Freescale MXC Implementations
└─>ARCH_MX53_SUPPORTED
In linux kernel since version 3 (release Date: 2011-07-21)  
depends
CONFIG_ARCH_MXC