net: mvpp2: set 802.3x GoP Flow Control mode

This patch fix GMAC TX flow control autoneg.
Flow control autoneg wrongly were disabled with enabled TX
flow control.
Signed-off-by: NStefan Chulski <stefanc@marvell.com>
Acked-by: NMarcin Wojtas <mw@semihalf.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c

@@ -6284,7 +6284,7 @@ static void mvpp2_gmac_config(struct mvpp2_port *port, unsigned int mode,
 	old_ctrl4 = ctrl4 = readl(port->base + MVPP22_GMAC_CTRL_4_REG);
 
 	ctrl0 &= ~MVPP2_GMAC_PORT_TYPE_MASK;
-	ctrl2 &= ~(MVPP2_GMAC_INBAND_AN_MASK | MVPP2_GMAC_PCS_ENABLE_MASK);
+	ctrl2 &= ~(MVPP2_GMAC_INBAND_AN_MASK | MVPP2_GMAC_PCS_ENABLE_MASK | MVPP2_GMAC_FLOW_CTRL_MASK);
 
 	/* Configure port type */
 	if (phy_interface_mode_is_8023z(state->interface)) {