net: stmmac: dwmac-qcom-ethqos: fix a regression on EMAC < 3

We must not assign plat_dat->dwmac4_addrs unconditionally as for
structures which don't set them, this will result in the core driver
using zeroes everywhere and breaking the driver for older HW. On EMAC < 2
the address should remain NULL.

Fixes: b683761 ("net: stmmac: dwmac-qcom-ethqos: Add EMAC3 support")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Andrew Halaney <ahalaney@redhat.com>
Reviewed-by: Siddharth Vadapalli <s-vadapalli@ti.com>
Reviewed-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c

@@ -644,7 +644,8 @@ static int qcom_ethqos_probe(struct platform_device *pdev)
 	plat_dat->fix_mac_speed = ethqos_fix_mac_speed;
 	plat_dat->dump_debug_regs = rgmii_dump;
 	plat_dat->has_gmac4 = 1;
-	plat_dat->dwmac4_addrs = &data->dwmac4_addrs;
+	if (ethqos->has_emac3)
+		plat_dat->dwmac4_addrs = &data->dwmac4_addrs;
 	plat_dat->pmt = 1;
 	plat_dat->tso_en = of_property_read_bool(np, "snps,tso");
 	if (of_device_is_compatible(np, "qcom,qcs404-ethqos"))