CONFIG_ARCH_MX1 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
default or selected kernelversion does not have config value CONFIG_ARCH_MX1.
Result is shown for kernelversion 6.5.1

CONFIG_ARCH_MX1 (not configurable)

configname: CONFIG_ARCH_MX1

Linux Kernel Configuration
└─>Freescale i.MX support
└─>ARCH_MX1
In linux kernel since version 2.6.29 (release Date: 2009-03-23)  
depends
CONFIG_ARCH_MXC

is selected by
CONFIG_VIDEO_MX1

is depended by
CONFIG_SOC_IMX1