CONFIG_MACH_NOKIA_RM680 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

Nokia N950 (RM-680) / N9 (RM-696) phones

modulename: board-rm680.ko

configname: CONFIG_MACH_NOKIA_RM680

Linux Kernel Configuration
└─>TI OMAP2/3/4 Specific Features
└─>Nokia N950 (RM-680) / N9 (RM-696) phones
In linux kernel since version 2.6.38 (release Date: 2011-03-14)  
source code:
/arch/arm/mach-omap2/
selects
CONFIG_MACH_NOKIA_RM696
CONFIG_OMAP_PACKAGE_CBB