axs101: fix dw gmac instantiation for updated dw gmac driver

With accepted change to DW GMAC driver -
92a190aaab (net/designware - switch driver
to phylib usage) we need to update this board because
"designware_initialize" now accepts only 2 parameters instead of 4.

Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Tom Rini <trini@ti.com>

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

board/synopsys/axs101/axs101.c

@@ -36,7 +36,7 @@ int board_mmc_init(bd_t *bis)
 
 int board_eth_init(bd_t *bis)
 {
-	if (designware_initialize(0, ARC_DWGMAC_BASE, 0,
+	if (designware_initialize(ARC_DWGMAC_BASE,
 				  PHY_INTERFACE_MODE_RGMII) >= 0)
 		return 1;