phylib: add RGMII-ID interface mode definition

The RGMII spec allows compliance for devices that implement an internal
delay on TXC or RXC inside the transmitter.  This patch adds an RGMII_ID
definition to support RGMII-ID devices in the phylib.

Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/include/linux/phy.h b/include/linux/phy.h
index edd4c88..2a659789f 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -55,6 +55,7 @@
 	PHY_INTERFACE_MODE_TBI,
 	PHY_INTERFACE_MODE_RMII,
 	PHY_INTERFACE_MODE_RGMII,
+	PHY_INTERFACE_MODE_RGMII_ID,
 	PHY_INTERFACE_MODE_RTBI
 } phy_interface_t;