imx: clock support enet2 anatop clock support

To i.MX6SX/UL, two ethernet interfaces are supported.
Add ENET2 clock support:
1. Introduce a new input parameter "fec_id", only 0 and 1 are allowed.
   To value 1, only i.MX6SX/UL can pass the check.
2. Modify board code who use this api to follow new api prototype.

Signed-off-by: Peng Fan <Peng.Fan@freescale.com>
Cc: Heiko Schocher <hs@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Stefan Roese <sr@denx.de>
Cc: Nikolaos Pasaloukos <Nikolaos.Pasaloukos@imgtec.com>
Cc: Stefano Babic <sbabic@denx.de>
Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/board/solidrun/mx6cuboxi/mx6cuboxi.c b/board/solidrun/mx6cuboxi/mx6cuboxi.c
index 9b1ecf0..8247e43 100644
--- a/board/solidrun/mx6cuboxi/mx6cuboxi.c
+++ b/board/solidrun/mx6cuboxi/mx6cuboxi.c
@@ -164,7 +164,7 @@
 	struct mii_dev *bus;
 	struct phy_device *phydev;
 
-	int ret = enable_fec_anatop_clock(ENET_25MHZ);
+	int ret = enable_fec_anatop_clock(0, ENET_25MHZ);
 	if (ret)
 		return ret;