prism: added rtc to list of expected i2c addresses.

Its absence is causing the POST I2C test to fail.

Change-Id: Ie5e44ec67bcd1d901777a1646f489a631147aaa5
diff --git a/board/mv_feroceon/mv_kw2/prism_sff.h b/board/mv_feroceon/mv_kw2/prism_sff.h
index 2afe53f..a161db8 100644
--- a/board/mv_feroceon/mv_kw2/prism_sff.h
+++ b/board/mv_feroceon/mv_kw2/prism_sff.h
@@ -35,7 +35,12 @@
 #define CC_DMI         "ccd"
 
 #if (defined(CONFIG_POST) && defined(CONFIG_SYS_POST_I2C))
-	#define I2C_ADDR_LIST   {SFF_ADDR_A0, SFF_ADDR_A2, 0x64}
+	#define I2C_ADDR_LIST {						\
+		SFF_ADDR_A0,						\
+		SFF_ADDR_A2,						\
+		0x64,							\
+		CONFIG_SYS_I2C_RTC_ADDR,				\
+	}
 
 	#define SFF_LOG(format, args...)
 	#define SFF_ERR_LOG(format, args...) \