Add phy-connection-type to gianfar nodes

The TSEC/eTSEC automatically detect their PHY interface type, unless
the type is RGMII-ID (RGMII with internal delay).  In that situation,
it just detects RGMII.  In order to fix this, we need to pass in rgmii-id
if that is the connection type.

Signed-off-by: Andy Fleming <afleming@freescale.com>
diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt
index 0c24348..76733a3 100644
--- a/Documentation/powerpc/booting-without-of.txt
+++ b/Documentation/powerpc/booting-without-of.txt
@@ -1250,6 +1250,12 @@
       network device.  This is used by the bootwrapper to interpret
       MAC addresses passed by the firmware when no information other
       than indices is available to associate an address with a device.
+    - phy-connection-type : a string naming the controller/PHY interface type,
+      i.e., "mii" (default), "rmii", "gmii", "rgmii", "rgmii-id", "sgmii",
+      "tbi", or "rtbi".  This property is only really needed if the connection
+      is of type "rgmii-id", as all other connection types are detected by
+      hardware.
+
 
   Example: