realtek: dsa: remove storm control

realtek: dsa: remove storm control

Commit 78bf3a5f44bf ("realtek: dsa: Fix rate control initialization") enabled
code setting up the "storm control" feature. This casued a speed regression
on rtl838x, reducing the effective max speed per port from line rate to around
500 Mbits/s.

Storm control is a policy feature with a number of input parameters depending
on use case and environment.  It is not possible to define a meaningful static
policy in the driver. The problem isn't just the arbitrary limits in the
current code.  Such features require userspace interfaces.

Drop this code for now. It wasn't missed while it was disabled.

Cc: Sven Eckelmann <se@simonwunderlich.de>
Fixes: 78bf3a5f44bf ("realtek: dsa: Fix rate control initialization")
Link: https://github.com/openwrt/openwrt/issues/21692
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Link: https://github.com/openwrt/openwrt/pull/21877
Signed-off-by: Robert Marko <robimarko@gmail.com>