dt-bindings: net: correct description of phy-connection-type

The phy-connection-type parameter is described in ePAPR 1.1:

Specifies interface type between the Ethernet device and a physical
layer (PHY) device. The value of this property is specific to the
implementation.

Signed-off-by: Madalin Bucur <madalin.bucur@oss.nxp.com>
Link: https://lore.kernel.org/r/1597917724-11127-1-git-send-email-madalin.bucur@oss.nxp.com
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/net/ethernet-controller.yaml

@@ -54,7 +54,8 @@ properties:
 
   phy-connection-type:
     description:
-      Operation mode of the PHY interface
+      Specifies interface type between the Ethernet device and a physical
+      layer (PHY) device.
     enum:
       # There is not a standard bus between the MAC and the PHY,
       # something proprietary is being used to embed the PHY in the