net: fsl_enetc: fix imdio register calculation

With commit cc4e8af2c552, fsl_enetc register accessors have been split to
handle different register offsets on different SoCs. However, for
internal MDIO register calculation, only ENETC_PM_IMDIO_BASE was fixed
without adding the SoC specific MAC register offset.

As a result, the network support for the Kontron SMARC-sAL28 and
probably other boards based on the LS1028A CPU is broken.

Add the SoC specific MAC register offset to calculation of imdio.priv to
fix this.

Fixes: cc4e8af2c552 ("net: fsl_enetc: Split register accessors")
Signed-off-by: Thomas Schaefer <thomas.schaefer@kontron.com>
Signed-off-by: Heiko Thiery <heiko.thiery@gmail.com>
Reviewed-by: Michael Walle <mwalle@kernel.org>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com> # LS1028A
Tested-by: Tim Harvey <tharvey@gateworks.com> # imx95_19x19_evk
Reviewed-by: Marek Vasut <marex@denx.de>
Reviewed-by: Alice Guo <alice.guo@nxp.com>
diff --git a/drivers/net/fsl_enetc.c b/drivers/net/fsl_enetc.c
index 52fa820..97cccda 100644
--- a/drivers/net/fsl_enetc.c
+++ b/drivers/net/fsl_enetc.c
@@ -473,13 +473,15 @@
 /* Apply protocol specific configuration to MAC, serdes as needed */
 static void enetc_start_pcs(struct udevice *dev)
 {
+	struct enetc_data *data = (struct enetc_data *)dev_get_driver_data(dev);
 	struct enetc_priv *priv = dev_get_priv(dev);
 
 	/* register internal MDIO for debug purposes */
 	if (enetc_read_pcapr_mdio(dev)) {
 		priv->imdio.read = enetc_mdio_read;
 		priv->imdio.write = enetc_mdio_write;
-		priv->imdio.priv = priv->port_regs + ENETC_PM_IMDIO_BASE;
+		priv->imdio.priv = priv->port_regs + data->reg_offset_mac +
+		                   ENETC_PM_IMDIO_BASE;
 		strlcpy(priv->imdio.name, dev->name, MDIO_NAME_LEN);
 		if (!miiphy_get_dev_by_name(priv->imdio.name))
 			mdio_register(&priv->imdio);