ARM: dts: imx6-sr-som: increase at8035 PHY gigabit Tw parameter

Increase the SmartEEE Tw parameter for Atheros PHYs to stop gigabit
links from sporadically dropping. Jon Nettleton found that a value
of 23 was the minimum to give a stable link, but testing with the
Com Express 7 module shows 24 is the minimum - so 23 may still be on
the margins. Use 24 instead for consistency across SolidRun platforms.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NShawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx6qdl-sr-som.dtsi

@@ -69,11 +69,13 @@
 		ethernet-phy@0 {
 			reg = <0>;
 			qca,clk-out-frequency = <125000000>;
+			qca,smarteee-tw-us-1g = <24>;
 		};
 
 		ethernet-phy@4 {
 			reg = <4>;
 			qca,clk-out-frequency = <125000000>;
+			qca,smarteee-tw-us-1g = <24>;
 		};
 	};
 };