default or selected kernelversion does not have config value CONFIG_FB_SUN3.
Result is shown for kernelversion 5.15.113

Sun3 framebuffer support

modulename: sun3fb.ko

configname: CONFIG_FB_SUN3

Linux Kernel Configuration
└─>Device Drivers
└─>Graphics support
└─>Sun3 framebuffer support
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
source code:
drivers/video/sun3fb.c
depends
CONFIG_BROKEN
CONFIG_FB
CONFIG_SUN3 or CONFIG_SUN3X