net: phy: RTL8211FVD: Restore disabling of PHY-mode EEE

When support for RTL8211F(D)(I)-VD-CG was introduced in commit
bb726b7 ("net: phy: realtek: add support for RTL8211F(D)(I)-VD-CG")
the implementation assumed that this PHY model doesn't have the
control register PHYCR2 (Page 0xa43 Address 0x19). This
assumption was based on the differences in CLKOUT configurations
between RTL8211FVD and the remaining RTL8211F PHYs. In the latter
commit 2c67301
("net: phy: realtek: Avoid PHYCR2 access if PHYCR2 not present")
this assumption was expanded to the PHY-mode EEE.

I performed tests on RTL8211FI-VD-CG and confirmed that disabling
PHY-mode EEE works correctly and is uniform with other PHYs
supported by the driver. To validate the correctness,
I contacted Realtek support. Realtek confirmed that PHY-mode EEE on
RTL8211F(D)(I)-VD-CG is configured via Page 0xa43 Address 0x19 bit 5.

Moreover, Realtek informed me that the most recent datasheet
for RTL8211F(D)(I)-VD-CG v1.1 is incomplete and the naming of
control registers is partly inconsistent. The errata I
received from Realtek corrects the naming as follows:

| Register                | Datasheet v1.1 | Errata |
|-------------------------|----------------|--------|
| Page 0xa44 Address 0x11 | PHYCR2         | PHYCR3 |
| Page 0xa43 Address 0x19 | N/A            | PHYCR2 |

This information confirms that the supposedly missing control register,
PHYCR2, exists in the RTL8211F(D)(I)-VD-CG under the same address and
the same name. It controls widely the same configs as other PHYs from
the RTL8211F series (e.g. PHY-mode EEE). Clock out configuration is an
exception.

Given all this information, restore disabling of the PHY-mode EEE.

Fixes: 2c67301 ("net: phy: realtek: Avoid PHYCR2 access if PHYCR2 not present")
Signed-off-by: Ivan Galkin <ivan.galkin@axis.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://patch.msgid.link/20251202-phy_eee-v1-1-fe0bf6ab3df0@axis.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Author: Ivan Galkin

drivers/net/phy/realtek/realtek_main.c

@@ -691,10 +691,6 @@ static int rtl8211f_config_aldps(struct phy_device *phydev)
 
 static int rtl8211f_config_phy_eee(struct phy_device *phydev)
 {
-	/* RTL8211FVD has no PHYCR2 register */
-	if (phydev->drv->phy_id == RTL_8211FVD_PHYID)
-		return 0;
-
 	/* Disable PHY-mode EEE so LPI is passed to the MAC */
 	return phy_modify_paged(phydev, RTL8211F_PHYCR_PAGE, RTL8211F_PHYCR2,
 				RTL8211F_PHYCR2_PHY_EEE_ENABLE, 0);