mx28evk: add RTC support

This patch adds support for the MX28 internal RTC
and enables u-boot's date command.

Signed-off-by: Matthias Fuchs <matthias.fuchs@esd.eu>
Tested-by: Fabio Estevam <fabio.estevam@freescale.com>

include/configs/mx28evk.h

@@ -56,6 +56,7 @@
 #define CONFIG_CMD_FAT
 
 #define CONFIG_CMD_CACHE
+#define CONFIG_CMD_DATE
 #define CONFIG_CMD_DHCP
 #define CONFIG_CMD_GPIO
 #define CONFIG_CMD_MII
@@ -150,6 +151,13 @@
 #endif
 
 /*
+ * RTC
+ */
+#ifdef	CONFIG_CMD_DATE
+#define	CONFIG_RTC_MXS
+#endif
+
+/*
  * Boot Linux
  */
 #define CONFIG_CMDLINE_TAG