net: fec: add phy-reset-duration for device tree probe

Different boards may require different phy reset duration.  Add property
phy-reset-duration for device tree probe, so that the boards that need
a longer reset duration can specify it in their device tree.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/Documentation/devicetree/bindings/net/fsl-fec.txt b/Documentation/devicetree/bindings/net/fsl-fec.txt
index 0428920..f7a2fef 100644
--- a/Documentation/devicetree/bindings/net/fsl-fec.txt
+++ b/Documentation/devicetree/bindings/net/fsl-fec.txt
@@ -11,6 +11,10 @@
 Optional properties:
 - local-mac-address : 6 bytes, mac address
 - phy-reset-gpios : Should specify the gpio for phy reset
+- phy-reset-duration : Reset duration in milliseconds.  Should present
+  only if property "phy-reset-gpios" is available.  Missing the property
+  will have the duration be 1 millisecond.  Numbers greater than 1000 are
+  invalid and 1 millisecond will be used instead.
 
 Example: