net: mvneta: program 1ms autonegotiation clock divisor

Program the 1ms autonegotiation clock divisor according to the clocking
rate of neta - without this, the 1ms clock ticks at about 660us on
Armada 38x configured for 250MHz. Bring this into correct specification.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Marek Behún <kabel@kernel.org>
Link: https://lore.kernel.org/r/E1ms4WD-00EKLK-Ld@rmk-PC.armlinux.org.ukSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/marvell/mvneta.c

@@ -3948,7 +3948,7 @@ static void mvneta_mac_config(struct phylink_config *config, unsigned int mode,
 	} else if (state->interface == PHY_INTERFACE_MODE_SGMII) {
 		/* SGMII mode receives the state from the PHY */
 		new_ctrl2 |= MVNETA_GMAC2_INBAND_AN_ENABLE;
-		new_clk |= MVNETA_GMAC_1MS_CLOCK_ENABLE;
+		new_clk = MVNETA_GMAC_1MS_CLOCK_ENABLE;
 		new_an = (new_an & ~(MVNETA_GMAC_FORCE_LINK_DOWN |
 				     MVNETA_GMAC_FORCE_LINK_PASS |
 				     MVNETA_GMAC_CONFIG_MII_SPEED |
@@ -3960,7 +3960,7 @@ static void mvneta_mac_config(struct phylink_config *config, unsigned int mode,
 	} else {
 		/* 802.3z negotiation - only 1000base-X */
 		new_ctrl0 |= MVNETA_GMAC0_PORT_1000BASE_X;
-		new_clk |= MVNETA_GMAC_1MS_CLOCK_ENABLE;
+		new_clk = MVNETA_GMAC_1MS_CLOCK_ENABLE;
 		new_an = (new_an & ~(MVNETA_GMAC_FORCE_LINK_DOWN |
 				     MVNETA_GMAC_FORCE_LINK_PASS |
 				     MVNETA_GMAC_CONFIG_MII_SPEED)) |
@@ -3973,6 +3973,10 @@ static void mvneta_mac_config(struct phylink_config *config, unsigned int mode,
 			new_an |= MVNETA_GMAC_AN_FLOW_CTRL_EN;
 	}
 
+	/* Set the 1ms clock divisor */
+	if (new_clk == MVNETA_GMAC_1MS_CLOCK_ENABLE)
+		new_clk |= clk_get_rate(pp->clk) / 1000;
+
 	/* Armada 370 documentation says we can only change the port mode
 	 * and in-band enable when the link is down, so force it down
 	 * while making these changes. We also do this for GMAC_CTRL2