CONFIG_MACH_U8500 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
U8500 Development platform
modulename: board-mop500.ko
and/orboard-mop500-u8500uib-rmi4.ko
configname: CONFIG_MACH_U8500
Linux Kernel Configuration
└─>Ux500 target platform
└─>U8500 Development platform
In linux kernel since version 2.6.38 (release Date: 2011-03-14)
Include support for the mop500 development platform.