wandboard: Remove duplicate 'mmc dev'

No need to call 'mmc dev' twice.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Acked-by: NOtavio Salvador <otavio@ossystems.com.br>

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; " \