mx51evk: Do not force the rootfs type

Currently mmcrootfstype is set to ext3 type.

It is better not to force it in the env vars, because users may prefer a
different file system type, so let's get rid of 'mmcrootfstype'.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Otavio Salvador <otavio@ossystems.com.br>

include/configs/mx51evk.h

@@ -160,11 +160,9 @@
 	"ip_dyn=yes\0" \
 	"mmcdev=0\0" \
 	"mmcpart=2\0" \
-	"mmcroot=/dev/mmcblk0p3 rw\0" \
-	"mmcrootfstype=ext3 rootwait\0" \
+	"mmcroot=/dev/mmcblk0p3 rootwait rw\0" \
 	"mmcargs=setenv bootargs console=ttymxc0,${baudrate} " \
-		"root=${mmcroot} " \
-		"rootfstype=${mmcrootfstype}\0" \
+		"root=${mmcroot}\0" \
 	"loadbootscript=" \
 		"fatload mmc ${mmcdev}:${mmcpart} ${loadaddr} ${script};\0" \
 	"bootscript=echo Running bootscript from mmc ...; " \