default or selected kernelversion does not have config value CONFIG_NET_DSA_TAG_KSZ9477.
Result is shown for kernelversion 6.5.1

CONFIG_NET_DSA_TAG_KSZ9477 (not configurable)

configname: CONFIG_NET_DSA_TAG_KSZ9477

Linux Kernel Configuration
└─>Networking support
└─>Networking options
└─>NET_DSA_TAG_KSZ9477
In linux kernel since version 5 (release Date: 2019-03-03)