dt-bindings: net: stm32-dwmac: Make each example a separate entry

Each independent example should be a separate entry. This allows for
'interrupts' to have different cell sizes.

The first example also has a phandle in 'interrupts', so drop the phandle.
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220106182518.1435497-8-robh@kernel.org

Documentation/devicetree/bindings/net/stm32-dwmac.yaml

@@ -108,7 +108,7 @@ examples:
            compatible = "st,stm32mp1-dwmac", "snps,dwmac-4.20a";
            reg = <0x5800a000 0x2000>;
            reg-names = "stmmaceth";
-           interrupts = <&intc GIC_SPI 61 IRQ_TYPE_LEVEL_HIGH>;
+           interrupts = <GIC_SPI 61 IRQ_TYPE_LEVEL_HIGH>;
            interrupt-names = "macirq";
            clock-names = "stmmaceth",
                      "mac-clk-tx",
@@ -127,6 +127,7 @@ examples:
            phy-mode = "rgmii";
        };
 
+  - |
     //Example 2 (MCU example)
      ethernet1: ethernet@40028000 {
            compatible = "st,stm32-dwmac", "snps,dwmac-3.50a";
@@ -142,6 +143,7 @@ examples:
            phy-mode = "mii";
        };
 
+  - |
     //Example 3
      ethernet2: ethernet@40027000 {
            compatible = "st,stm32-dwmac", "snps,dwmac-4.10a";