realtek: board: some family check cleanups

realtek: board: some family check cleanups

The prom initialization is a bit of a mess now with all these
model and soc family checks. And realtek_read_model() function
is the worst offender of all as it goes through all of the model
info register from different SoCs just to read details from one
of them.

We can make use of the .data property in realtek_of_match to
clean things up so that each soc family has its own way of
initialization and reading model details.

Create a struct that will be used for that and add all of the
soc data structs for all chip families.

With all that, remove realtek_read_model() function and most
of the soc_info.family checks in various functions.

In addition, add the rtl960x compatibles along as well so that
rtl960x model info details has somewhere to be used. RTL8198D
is also added as it is part of RTL9607C family.

Signed-off-by: Rustam Adilov <adilov@tutamail.com>
Link: https://github.com/openwrt/openwrt/pull/24588
Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>