ppc4xx: Allow DTT_I2C_DEV_CODE configured by CFG_I2C_DTT_ADDR

On AMCC Arches board DTT_I2C_DEV_CODE is different then canyonlands
and glacier.

Signed-off-by: Victor Gallardo <vgallardo@amcc.com>
diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c
index 8051cb2..67a18f6 100644
--- a/drivers/hwmon/lm75.c
+++ b/drivers/hwmon/lm75.c
@@ -38,7 +38,11 @@
 /*
  * Device code
  */
+#if defined(CFG_I2C_DTT_ADDR)
+#define DTT_I2C_DEV_CODE CFG_I2C_DTT_ADDR
+#else
 #define DTT_I2C_DEV_CODE 0x48			/* ON Semi's LM75 device */
+#endif
 #define DTT_READ_TEMP		0x0
 #define DTT_CONFIG		0x1
 #define DTT_TEMP_HYST		0x2