amd-xgbe: Remove field that indicates SFP diagnostic support

The driver currently sets an indication of whether the SFP supports, and
that the driver can obtain, diagnostics data.  This isn't currently used
by the driver and the logic to set this indicator is flawed because the
field is cleared each time the SFP is checked and only set when a new SFP
is detected.  Remove this field and the logic supporting it.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c

@@ -343,7 +343,6 @@ struct xgbe_phy_data {
 	unsigned int sfp_rx_los;
 	unsigned int sfp_tx_fault;
 	unsigned int sfp_mod_absent;
-	unsigned int sfp_diags;
 	unsigned int sfp_changed;
 	unsigned int sfp_phy_avail;
 	unsigned int sfp_cable_len;
@@ -1211,13 +1210,6 @@ static int xgbe_phy_sfp_read_eeprom(struct xgbe_prv_data *pdata)
 
 		memcpy(&phy_data->sfp_eeprom, &sfp_eeprom, sizeof(sfp_eeprom));
 
-		if (sfp_eeprom.extd[XGBE_SFP_EXTD_SFF_8472]) {
-			u8 diag_type = sfp_eeprom.extd[XGBE_SFP_EXTD_DIAG];
-
-			if (!(diag_type & XGBE_SFP_EXTD_DIAG_ADDR_CHANGE))
-				phy_data->sfp_diags = 1;
-		}
-
 		xgbe_phy_free_phy_device(pdata);
 	} else {
 		phy_data->sfp_changed = 0;
@@ -1267,7 +1259,6 @@ static void xgbe_phy_sfp_reset(struct xgbe_phy_data *phy_data)
 	phy_data->sfp_rx_los = 0;
 	phy_data->sfp_tx_fault = 0;
 	phy_data->sfp_mod_absent = 1;
-	phy_data->sfp_diags = 0;
 	phy_data->sfp_base = XGBE_SFP_BASE_UNKNOWN;
 	phy_data->sfp_cable = XGBE_SFP_CABLE_UNKNOWN;
 	phy_data->sfp_speed = XGBE_SFP_SPEED_UNKNOWN;