dt-binding: net/phy: fix interrupts description

Commit b053dc5a (powerpc: Refactor device tree binding) split the
Ethernet PHY binding documentation out of the big booting-without-of.txt
file, leaving a dangling reference to "section 2" in the 'interrupts'
property description. Drop that reference, and make the description look
more like the rest.

While at it, make the example interrupt-parent phandle look more like a
real world phandle, and use an IRQ_TYPE_ macro for the 'interrupts'
type.
Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Signed-off-by: NRob Herring <robh@kernel.org>

Documentation/devicetree/bindings/net/phy.txt

@@ -2,11 +2,7 @@ PHY nodes
 
 Required properties:
 
- - interrupts : <a b> where a is the interrupt number and b is a
-   field that represents an encoding of the sense and level
-   information for the interrupt.  This should be encoded based on
-   the information in section 2) depending on the type of interrupt
-   controller you have.
+ - interrupts : interrupt specifier for the sole interrupt.
  - interrupt-parent : the phandle for the interrupt controller that
    services interrupts for this device.
  - reg : The ID number for the phy, usually a small integer
@@ -56,7 +52,7 @@ Example:
 
 ethernet-phy@0 {
 	compatible = "ethernet-phy-id0141.0e90", "ethernet-phy-ieee802.3-c22";
-	interrupt-parent = <40000>;
-	interrupts = <35 1>;
+	interrupt-parent = <&PIC>;
+	interrupts = <35 IRQ_TYPE_EDGE_RISING>;
 	reg = <0>;
 };