CONFIG_ARC_FPU_SAVE_RESTORE is not available for thedefaultarchitecture x86.
Result is shown for architecture arc

Enable FPU state persistence across context switch

modulename: fpu.ko

configname: CONFIG_ARC_FPU_SAVE_RESTORE

Linux Kernel Configuration
└─>ARC Architecture Configuration
└─>ARC CPU Configuration
└─>Enable FPU state persistence across context switch
In linux kernel since version 3.1 (release Date: 2011-10-24)  
ARCompact FPU has internal registers to assist with Double precision
Floating Point operations. There are control and stauts registers
for floating point exceptions and rounding modes. These are
preserved across task context switch when enabled.

source code:
is depended by
CONFIG_ARC_SOC_HSDK