default or selected kernelversion does not have config value CONFIG_SPACEMIT_K1_EMAC.
Result is shown for kernelversion 6.18-rc3

SpacemiT K1 Ethernet MAC driver

modulename: k1_emac.ko

configname: CONFIG_SPACEMIT_K1_EMAC

Linux Kernel Configuration
└─>Device Drivers
└─>Network device support
└─>Ethernet driver support
└─>Device Tree and Open Firmware support
└─>SpacemiT K1 Ethernet MAC driver
This driver supports the Ethernet MAC in the SpacemiT K1 SoC.

To compile this driver as a module, choose M here: the module
will be called k1_emac.

source code:
drivers/net/ethernet/spacemit/k1_emac.c
selects
CONFIG_PHYLIB