net: micrel: Fix wrong function name in comments

Fixes the following W=1 kernel build warning(s):

 drivers/net/ethernet/micrel/ksz884x.c:2163: warning: expecting prototype for sw_get_board_storm(). Prototype was for sw_get_broad_storm() instead
 drivers/net/ethernet/micrel/ksz884x.c:2985: warning: expecting prototype for port_w_phy(). Prototype was for hw_w_phy() instead
 drivers/net/ethernet/micrel/ksz884x.c:4792: warning: expecting prototype for transmit_done(). Prototype was for tx_done() instead

Cc: Tristram Ha <Tristram.Ha@micrel.com>
Signed-off-by: Yang Shen <shenyang39@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>