net: pcs: pcs-mtk-lynxi: report in-band capability for 2500Base-X

It turns out that 2500Base-X actually works fine with in-band status on
MediaTek's LynxI PCS -- I wrongly concluded it didn't because it is
broken in all the copper SFP modules and GPON sticks I used for testing.

Hence report LINK_INBAND_ENABLE also for 2500Base-X mode.

This reverts most of commit a003c38 ("net: pcs: pcs-mtk-lynxi:
correctly report in-band status capabilities").

The removal of the QSGMII interface mode was correct and is left
untouched.

Link: openwrt/openwrt#21436
Fixes: a003c38 ("net: pcs: pcs-mtk-lynxi: correctly report in-band status capabilities")
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Link: https://patch.msgid.link/b1cf26157b63fee838be09ae810497fb22fd8104.1768961746.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: dangowrt

drivers/net/pcs/pcs-mtk-lynxi.c

@@ -93,12 +93,10 @@ static unsigned int mtk_pcs_lynxi_inband_caps(struct phylink_pcs *pcs,
 {
 	switch (interface) {
 	case PHY_INTERFACE_MODE_1000BASEX:
+	case PHY_INTERFACE_MODE_2500BASEX:
 	case PHY_INTERFACE_MODE_SGMII:
 		return LINK_INBAND_DISABLE | LINK_INBAND_ENABLE;
 
-	case PHY_INTERFACE_MODE_2500BASEX:
-		return LINK_INBAND_DISABLE;
-
 	default:
 		return 0;
 	}