net: mscc: ocelot: remove buggy duplicate write to DEV_CLOCK_CFG

When updating ocelot to use phylink, a second write to DEV_CLOCK_CFG was
mistakenly left in. It used the variable "speed" which, previously, would
would have been assigned a value of OCELOT_SPEED_1000. In phylink the
variable is be SPEED_1000, which is invalid for the
DEV_CLOCK_LINK_SPEED macro. Removing it as unnecessary and buggy.

Fixes: e6e12df6 ("net: mscc: ocelot: convert to phylink")
Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>