CONFIG_ROCKHOPPER is not available for thedefaultarchitecture x86.
Result is shown for architecture mips
default or selected kernelversion does not have config value CONFIG_ROCKHOPPER.
Result is shown for kernelversion 5.4.123

Support for Rockhopper baseboard

modulename: irq.ko

configname: CONFIG_ROCKHOPPER

Linux/MIPS Kernel Configuration
└─>Machine selection
└─>Support for Rockhopper baseboard
In linux kernel since version 2.6.12  
source code: