The hardware value of 3 for WiFi 7 chips is padding 16 or 20us selected
by hardware automatically. Correct the value to resolve interoperability
problem. Also define enum to be more readable.
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://msgid.link/20240517013639.11643-1-pkshih@realtek.com