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/freescale/mx6qsabreauto/mx6qsabreauto.c b/board/freescale/mx6qsabreauto/mx6qsabreauto.c
index 98602f8..7c0e90a 100644
--- a/board/freescale/mx6qsabreauto/mx6qsabreauto.c
+++ b/board/freescale/mx6qsabreauto/mx6qsabreauto.c
@@ -361,7 +361,7 @@
 		 * select ENET MAC0 TX clock from PLL
 		 */
 		imx_iomux_set_gpr_register(5, 9, 1, 1);
-		enable_fec_anatop_clock(ENET_125MHZ);
+		enable_fec_anatop_clock(0, ENET_125MHZ);
 	}
 
 	setup_iomux_enet();