CONFIG_MACH_MOP500 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
default or selected kernelversion does not have config value CONFIG_MACH_MOP500.
Result is shown for kernelversion 6.7-rc3

U8500 Development platform, MOP500 versions

configname: CONFIG_MACH_MOP500

Linux Kernel Configuration
└─>ST-Ericsson U8500 Series
└─>U8500 Development platform, MOP500 versions
In linux kernel since version 3.1 (release Date: 2011-10-24)  
Include support for the MOP500 development platform.