default or selected kernelversion does not have config value CONFIG_DRM_SIS.
Result is shown for kernelversion 6.9.9

SiS video cards

modulename: sis.ko

configname: CONFIG_DRM_SIS

Linux Kernel Configuration
└─>Device Drivers
└─>Graphics support
└─>Enable legacy drivers (DANGEROUS)
└─>Direct Rendering Manager (XFree86 4.1.0 and higher DRI support)
└─>/dev/agpgart (AGP Support)
└─>SiS video cards
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
Choose this option if you have a SiS 630 or compatible video
chipset. If M is selected the module will be called sis. AGP
support is required for this driver to work.

source code: