net: mdio: mscc-miim: fix duplicate debugfs entry

This driver can have up to two regmaps. If the second one is registered
its debugfs entry will have the same name as the first one and the
following error will be printed:

[    3.833521] debugfs: Directory 'e200413c.mdio' with parent 'regmap' already present!

Give the second regmap a name to avoid this.

Fixes: a27a7628 ("net: mdio: mscc-miim: convert to a regmap implementation")
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20220312224140.4173930-1-michael@walle.ccSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/mdio/mdio-mscc-miim.c

@@ -187,6 +187,13 @@ static const struct regmap_config mscc_miim_regmap_config = {
 	.reg_stride	= 4,
 };
 
+static const struct regmap_config mscc_miim_phy_regmap_config = {
+	.reg_bits	= 32,
+	.val_bits	= 32,
+	.reg_stride	= 4,
+	.name		= "phy",
+};
+
 int mscc_miim_setup(struct device *dev, struct mii_bus **pbus, const char *name,
 		    struct regmap *mii_regmap, int status_offset)
 {
@@ -250,7 +257,7 @@ static int mscc_miim_probe(struct platform_device *pdev)
 		}
 
 		phy_regmap = devm_regmap_init_mmio(&pdev->dev, phy_regs,
-						   &mscc_miim_regmap_config);
+						   &mscc_miim_phy_regmap_config);
 		if (IS_ERR(phy_regmap)) {
 			dev_err(&pdev->dev, "Unable to create phy register regmap\n");
 			return PTR_ERR(phy_regmap);