ice: use eth_broadcast_addr() to set broadcast address

Use eth_broadcast_addr() to set broadcast address instead of memset().

Signed-off-by: Lu Wei <luwei32@huawei.com>
Tested-by: Gurucharan <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>