cmd: add Kconfig option for 'date' command

Signed-off-by: Chris Packham <judge.packham@gmail.com>
[trini: default y if DM_RTC, re-sync]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/devconcenter_defconfig b/configs/devconcenter_defconfig
index f6b6c95..1c16ed2 100644
--- a/configs/devconcenter_defconfig
+++ b/configs/devconcenter_defconfig
@@ -22,6 +22,7 @@
 CONFIG_CMD_PING=y
 CONFIG_CMD_SNTP=y
 CONFIG_CMD_CACHE=y
+CONFIG_CMD_DATE=y
 CONFIG_CMD_EXT2=y
 CONFIG_CMD_FAT=y
 CONFIG_MAC_PARTITION=y