B4860QDS: Enable SFP or AMC on basis of hwconfig string

SerDes2 lanes EFGH either go to SFP or AMC riser card slot2.
By default AMC will be configured even if no hwconfig is specified.

To enable XFI via SFP use the below hwconfig:
	fsl_b4860_serdes2:sfp_amc=sfp
Signed-off-by: NSuresh Gupta <suresh.gupta@freescale.com>
Signed-off-by: NPoonam Aggrwal <poonam.aggrwal@ffeescale.com>
Signed-off-by: NShaohui Xie <Shaohui.Xie@freescale.com>
Reviewed-by: NYork Sun <yorksun@freescale.com>

board/freescale/b4860qds/b4860qds.c

@@ -19,6 +19,7 @@
 #include <asm/fsl_portals.h>
 #include <asm/fsl_liodn.h>
 #include <fm_eth.h>
+#include <hwconfig.h>
 
 #include "../common/qixis.h"
 #include "../common/vsc3316_3308.h"
@@ -333,6 +334,8 @@ int configure_vsc3316_3308(void)
 	unsigned int num_vsc16_con, num_vsc08_con;
 	u32 serdes1_prtcl, serdes2_prtcl;
 	int ret;
+	char buffer[HWCONFIG_BUFFER_SIZE];
+	char *buf = NULL;
 
 	serdes1_prtcl = in_be32(&gur->rcwsr[4]) &
 			FSL_CORENET2_RCWSR4_SRDS1_PRTCL;
@@ -536,14 +539,36 @@ int configure_vsc3316_3308(void)
 	case 0xb1:
 	case 0xb2:
 		if (!ret) {
-			ret = vsc3308_config(VSC3308_TX_ADDRESS,
-					vsc08_tx_sfp, num_vsc08_con);
-			if (ret)
-				return ret;
-			ret = vsc3308_config(VSC3308_RX_ADDRESS,
-					vsc08_rx_sfp, num_vsc08_con);
-			if (ret)
-				return ret;
+			/*
+			 * Extract hwconfig from environment since environment
+			 * is not setup properly yet
+			 */
+			getenv_f("hwconfig", buffer, sizeof(buffer));
+			buf = buffer;
+
+			if (hwconfig_subarg_cmp_f("fsl_b4860_serdes2",
+						  "sfp_amc", "sfp", buf)) {
+				ret = vsc3308_config(VSC3308_TX_ADDRESS,
+						vsc08_tx_sfp, num_vsc08_con);
+				if (ret)
+					return ret;
+
+				ret = vsc3308_config(VSC3308_RX_ADDRESS,
+						vsc08_rx_sfp, num_vsc08_con);
+				if (ret)
+					return ret;
+			} else {
+				ret = vsc3308_config(VSC3308_TX_ADDRESS,
+						vsc08_tx_amc, num_vsc08_con);
+				if (ret)
+					return ret;
+
+				ret = vsc3308_config(VSC3308_RX_ADDRESS,
+						vsc08_rx_amc, num_vsc08_con);
+				if (ret)
+					return ret;
+			}
+
 		} else {
 			return ret;
 		}