wandboard: Remove duplicate 'mmc dev'

No need to call 'mmc dev' twice.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Otavio Salvador <otavio@ossystems.com.br>
diff --git a/include/configs/wandboard.h b/include/configs/wandboard.h
index c4fb704..00c656e 100644
--- a/include/configs/wandboard.h
+++ b/include/configs/wandboard.h
@@ -150,7 +150,6 @@
 		"fi;\0"
 
 #define CONFIG_BOOTCOMMAND \
-	   "mmc dev ${mmcdev};" \
 	   "mmc dev ${mmcdev}; if mmc rescan; then " \
 		   "if run loadbootscript; then " \
 			   "run bootscript; " \