[POWERPC] fsl_soc: add support to gianfar for fixed-link property

fixed-link says: register new "Fixed/emulated PHY", i.e. PHY that
not connected to the real MDIO bus.

Signed-off-by: Vitaly Bordug <vitb@kernel.crashing.org>
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt
index e58fd31..f920c24 100644
--- a/Documentation/powerpc/booting-without-of.txt
+++ b/Documentation/powerpc/booting-without-of.txt
@@ -1257,6 +1257,10 @@
       services interrupts for this device.
     - phy-handle : The phandle for the PHY connected to this ethernet
       controller.
+    - fixed-link : <a b c d e> where a is emulated phy id - choose any,
+      but unique to the all specified fixed-links, b is duplex - 0 half,
+      1 full, c is link speed - d#10/d#100/d#1000, d is pause - 0 no
+      pause, 1 pause, e is asym_pause - 0 no asym_pause, 1 asym_pause.
 
   Recommended properties: