default or selected kernelversion does not have config value CONFIG_S6GMAC.
Result is shown for kernelversion 6.5.1

S6105 GMAC ethernet support

modulename: s6gmac.ko

configname: CONFIG_S6GMAC

Linux Kernel Configuration
└─>Device Drivers
└─>Network device support
└─>Ethernet driver support
└─>S6105 GMAC ethernet support
In linux kernel since version 2.6.31 (release Date: 2009-09-09)  
This driver supports the on chip ethernet device on the
S6105 xtensa processor.

To compile this driver as a module, choose M here. The module
will be called s6gmac.

source code: