Add support for the DS3231 RTC


diff --git a/include/configs/spc1920.h b/include/configs/spc1920.h
index a836d82..c6b4d30 100644
--- a/include/configs/spc1920.h
+++ b/include/configs/spc1920.h
@@ -83,6 +83,7 @@
 #ifndef CONFIG_COMMANDS
 #define CONFIG_COMMANDS	(CONFIG_CMD_DFL   \
 			 | CFG_CMD_ASKENV \
+			 | CFG_CMD_DATE \
 			 | CFG_CMD_ECHO   \
 			 | CFG_CMD_IMMAP  \
 			 | CFG_CMD_JFFS2 \
@@ -194,6 +195,11 @@
 #define CFG_CACHELINE_SIZE	16	/* For all MPC8xx CPUs			*/
 #define CFG_CACHELINE_SHIFT	4	/* log base 2 of the above value	*/
 
+#ifdef CFG_CMD_DATE
+# define CONFIG_RTC_DS3231
+# define CFG_I2C_RTC_ADDR      0x68
+#endif
+
 /*-----------------------------------------------------------------------
  * I2C configuration
  */