[PATCH] I2C: Add support for multiple I2C busses for RTC & DTT

This patch switches to the desired I2C bus when the date/dtt
commands are called. This can be configured using the
CFG_RTC_BUS_NUM and/or CFG_DTT_BUS_NUM defines.

Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/dtt/adm1021.c b/dtt/adm1021.c
index 14c38f0..9f65cfb 100644
--- a/dtt/adm1021.c
+++ b/dtt/adm1021.c
@@ -144,12 +144,15 @@
 	unsigned char sensors[] = CONFIG_DTT_SENSORS;
 	const char *const header = "DTT:   ";
 
+	/* switch to correct I2C bus */
+	I2C_SET_BUS(CFG_DTT_BUS_NUM);
+
 	for (i = 0; i < sizeof(sensors); i++) {
-	    if (_dtt_init(sensors[i]) != 0)
-		printf ("%s%d FAILED INIT\n", header, i+1);
-	    else
-		printf ("%s%d is %i C\n", header, i+1,
-		       dtt_get_temp(sensors[i]));
+		if (_dtt_init(sensors[i]) != 0)
+			printf ("%s%d FAILED INIT\n", header, i+1);
+		else
+			printf ("%s%d is %i C\n", header, i+1,
+				dtt_get_temp(sensors[i]));
 	}
 
 	return (0);