This allows specifying interval of polling MIB counters from userspace
and allow completely turning off MIB counter support by setting
mib_poll_interval to 0.
Since MIB counter polling is a heavy CPU load for GPIO emulated MDIO
bus, disable this behavior by default. Those who wants to use swconfig
LEDs can enable them with qca,mib-poll-interval dts property or with
swconfig command.
Fixes: FS#2230 ("kworker spikes 100% cpu every 2 second.")
Signed-off-by: Chuanhong Guo <gch981213@gmail.com>
107dc4326c