net/fm: add 2.5G SGMII support

As auto-negotiation is not supported for 2.5G SGMII, we need
to add a new type PHY_INTERFACE_MODE_SGMII_2500 to differentiate
SGMII-1G and SGMII-2.5G with different setting for auto-negotiation.

Signed-off-by: Shaohui Xie <Shaohui.Xie@freescale.com>
Signed-off-by: Shengzhou Liu <Shengzhou.Liu@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>
diff --git a/include/phy.h b/include/phy.h
index b495077..d430ed0 100644
--- a/include/phy.h
+++ b/include/phy.h
@@ -41,6 +41,7 @@
 	PHY_INTERFACE_MODE_MII,
 	PHY_INTERFACE_MODE_GMII,
 	PHY_INTERFACE_MODE_SGMII,
+	PHY_INTERFACE_MODE_SGMII_2500,
 	PHY_INTERFACE_MODE_QSGMII,
 	PHY_INTERFACE_MODE_TBI,
 	PHY_INTERFACE_MODE_RMII,
@@ -57,6 +58,7 @@
 	[PHY_INTERFACE_MODE_MII]		= "mii",
 	[PHY_INTERFACE_MODE_GMII]		= "gmii",
 	[PHY_INTERFACE_MODE_SGMII]		= "sgmii",
+	[PHY_INTERFACE_MODE_SGMII_2500]		= "sgmii-2500",
 	[PHY_INTERFACE_MODE_QSGMII]		= "qsgmii",
 	[PHY_INTERFACE_MODE_TBI]		= "tbi",
 	[PHY_INTERFACE_MODE_RMII]		= "rmii",