net: phy: aquantia: AQR115c fix up PMA capabilities

AQR115c reports incorrect PMA capabilities which includes
10G/5G and also incorrectly disables capabilities like autoneg
and 10Mbps support.

AQR115c as per the Marvell databook supports speeds up to 2.5Gbps
with autonegotiation.

Fixes: 0ebc581 ("net: phy: aquantia: add support for aqr115c")
Link: https://lore.kernel.org/all/20240913011635.1286027-1-quic_abchauha@quicinc.com/T/
Signed-off-by: Abhishek Chauhan <quic_abchauha@quicinc.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/20241001224626.2400222-2-quic_abchauha@quicinc.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: Abhishek Chauhan

drivers/net/phy/aquantia/aquantia_main.c

@@ -731,6 +731,19 @@ static int aqr113c_fill_interface_modes(struct phy_device *phydev)
 	return aqr107_fill_interface_modes(phydev);
 }
 
+static int aqr115c_get_features(struct phy_device *phydev)
+{
+	unsigned long *supported = phydev->supported;
+
+	/* PHY supports speeds up to 2.5G with autoneg. PMA capabilities
+	 * are not useful.
+	 */
+	linkmode_or(supported, supported, phy_gbit_features);
+	linkmode_set_bit(ETHTOOL_LINK_MODE_2500baseT_Full_BIT, supported);
+
+	return 0;
+}
+
 static int aqr113c_config_init(struct phy_device *phydev)
 {
 	int ret;
@@ -1046,6 +1059,7 @@ static struct phy_driver aqr_driver[] = {
 	.get_sset_count = aqr107_get_sset_count,
 	.get_strings    = aqr107_get_strings,
 	.get_stats      = aqr107_get_stats,
+	.get_features   = aqr115c_get_features,
 	.link_change_notify = aqr107_link_change_notify,
 	.led_brightness_set = aqr_phy_led_brightness_set,
 	.led_hw_is_supported = aqr_phy_led_hw_is_supported,