am3517evm: remove rootfstype kernel parameter for MMC boot device

it is not necessary to define rootfstype for mass storage devices.
Kernel detects it automatically.

Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>

include/configs/am3517_evm.h

@@ -192,8 +192,7 @@
 	"console=ttyO2,115200n8\0" \
 	"mmcdev=0\0" \
 	"mmcargs=setenv bootargs console=${console} " \
-		"root=/dev/mmcblk0p2 rw " \
-		"rootfstype=ext3 rootwait\0" \
+		"root=/dev/mmcblk0p2 rw rootwait\0" \
 	"nandargs=setenv bootargs console=${console} " \
 		"root=/dev/mtdblock4 rw " \
 		"rootfstype=jffs2\0" \