mpc5200: digsy_mtc: fix extension board EEPROM I2C address for rev5

On newer rev5 hardware the extension board EEPROM I2C address
has been changed to 0x54. Make this I2C address configurable
depending on CONFIG_DIGSY_REV5 so that extention board presence
detection works correctly on newer hardware.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
diff --git a/board/intercontrol/digsy_mtc/digsy_mtc.c b/board/intercontrol/digsy_mtc/digsy_mtc.c
index 784ba2a..4d6b33d 100644
--- a/board/intercontrol/digsy_mtc/digsy_mtc.c
+++ b/board/intercontrol/digsy_mtc/digsy_mtc.c
@@ -220,9 +220,6 @@
 
 #define GPT_GPIO_ON		0x00000034	/* GPT as simple GPIO, high */
 
-/* ExBo I2C Addresses */
-#define EXBO_EE_I2C_ADDRESS	0x56
-
 static void exbo_hw_init(void)
 {
 	struct mpc5xxx_gpt *gpt = (struct mpc5xxx_gpt *)MPC5XXX_GPT;
@@ -232,7 +229,7 @@
 	unsigned char val;
 
 	/* 1st, check if extension board is present */
-	if (i2c_read(EXBO_EE_I2C_ADDRESS, 0, 1, &val, 1))
+	if (i2c_read(CONFIG_SYS_EXBO_EE_I2C_ADDRESS, 0, 1, &val, 1))
 		return;
 
 	/* configure IrDA pins (PSC6 port) as gpios */
diff --git a/include/configs/digsy_mtc.h b/include/configs/digsy_mtc.h
index ec5223c..522ec57 100644
--- a/include/configs/digsy_mtc.h
+++ b/include/configs/digsy_mtc.h
@@ -288,6 +288,13 @@
 #define CONFIG_SYS_DS1339_TCR_VAL	0xAB	/* diode + 4k resistor */
 #endif
 
+/* ExBo I2C Addresses */
+#if defined(CONFIG_DIGSY_REV5)
+#define CONFIG_SYS_EXBO_EE_I2C_ADDRESS	0x54
+#else
+#define CONFIG_SYS_EXBO_EE_I2C_ADDRESS	0x56
+#endif
+
 /*
  * Flash configuration
  */