dt-bindings: net: renesas,ravb: Document internal clock delay properties

Some EtherAVB variants support internal clock delay configuration, which
can add larger delays than the delays that are typically supported by
the PHY (using an "rgmii-*id" PHY mode, and/or "[rt]xc-skew-ps"
properties).

Add properties for configuring the internal MAC delays.
These properties are mandatory, even when specified as zero, to
distinguish between old and new DTBs.

Update the (bogus) example accordingly.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Sergei Shtylyov <sergei.shtylyov@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/renesas,ravb.txt

@@ -64,6 +64,18 @@ Optional properties:
 			 AVB_LINK signal.
 - renesas,ether-link-active-low: boolean, specify when the AVB_LINK signal is
 				 active-low instead of normal active-high.
+- rx-internal-delay-ps: Internal RX clock delay.
+			This property is mandatory and valid only on R-Car Gen3
+			and RZ/G2 SoCs.
+			Valid values are 0 and 1800.
+			A non-zero value is allowed only if phy-mode = "rgmii".
+			Zero is not supported on R-Car D3.
+- tx-internal-delay-ps: Internal TX clock delay.
+			This property is mandatory and valid only on R-Car H3,
+			M3-W, M3-W+, M3-N, V3M, and V3H, and RZ/G2M and RZ/G2N.
+			Valid values are 0 and 2000.
+			A non-zero value is allowed only if phy-mode = "rgmii".
+			Zero is not supported on R-Car V3H.
 
 Example:
 
@@ -105,8 +117,10 @@ Example:
 				  "ch24";
 		clocks = <&cpg CPG_MOD 812>;
 		power-domains = <&cpg>;
-		phy-mode = "rgmii-id";
+		phy-mode = "rgmii";
 		phy-handle = <&phy0>;
+		rx-internal-delay-ps = <0>;
+		tx-internal-delay-ps = <2000>;
 
 		pinctrl-0 = <&ether_pins>;
 		pinctrl-names = "default";
@@ -115,18 +129,7 @@ Example:
 		#size-cells = <0>;
 
 		phy0: ethernet-phy@0 {
-			rxc-skew-ps = <900>;
-			rxdv-skew-ps = <0>;
-			rxd0-skew-ps = <0>;
-			rxd1-skew-ps = <0>;
-			rxd2-skew-ps = <0>;
-			rxd3-skew-ps = <0>;
-			txc-skew-ps = <900>;
-			txen-skew-ps = <0>;
-			txd0-skew-ps = <0>;
-			txd1-skew-ps = <0>;
-			txd2-skew-ps = <0>;
-			txd3-skew-ps = <0>;
+			rxc-skew-ps = <1500>;
 			reg = <0>;
 			interrupt-parent = <&gpio2>;
 			interrupts = <11 IRQ_TYPE_LEVEL_LOW>;