CONFIG_NIOS2_HW_DIV_SUPPORT is not available for thedefaultarchitecture x86.
Result is shown for architecture nios2

Enable DIV instruction


Linux Kernel Configuration
└─>Platform options
└─>Enable DIV instruction
In linux kernel since version 3.19 (release Date: 2015-02-08)  
Set to true if you configured the Nios II to include the DIV
instruction. Enables the -mhw-div compiler flag.