net: dsa: microchip: move broadcast rate limit to ksz_setup

This patch move the 10% broadcast protection from the individual setup
to ksz_setup. In the ksz9477, broadcast protection is updated in reset
function.

Signed-off-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>