Currently, tas_data->enabled would remain true even after deleting all
tc-gate rules from the switch ports, which would cause the
sja1105_tas_state_machine to get unnecessarily scheduled.

Also, if there were any errors which would prevent the hardware from
enabling the gating schedule, the sja1105_tas_state_machine would
continuously detect and print that, spamming the kernel log, even if the
rules were subsequently deleted.

The rules themselves are _not_ active, because sja1105_init_scheduling
does enough of a job to not install the gating schedule in the static
config. But the virtual link rules themselves are still present.

So call the functions that remove the tc-gate configuration from
priv->tas_data.gating_cfg, so that tas_data->enabled can be set to
false, and sja1105_tas_state_machine will stop from being scheduled.

Fixes: 834f8933 ("net: dsa: sja1105: implement tc-gate using time-triggered virtual links")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>