Address review by documenting regget 4 and RTL8373 N/non-N ID values under Step 4 of adding-a-device.md, without referring to a particular board or set of units. Keep the verified Horaco CPU and flash capacity in its device table and retain the unverified-chip caveat.
Read register 0x0004 on all three tested HC-SWTGW218AS units. Each returned 0x83730000, identifying RTL8373 rather than RTL8373N. Firmware reports 2 MB flash on all three.
Fill in the verified device-table fields and document the non-N/N register distinction. Leave PHY and flash-chip models explicitly unverified.
The HC-SWTGW218AS is listed only with the SWTG018AS-A V2.0 board, but it
also ships with SWTG118AS-V2.1, the board of the XikeStor SKS3200-8E1X.
That version runs MACHINE=SWTGW218AS: three such switches were flashed
through the OEM web upgrade and work.
Note in the device page that the model name alone does not tell which
firmware to build.