wandboard: Remove hardcoded baudrate from "console" variable

We should use the baudrate variable available inside U-Boot
environment to allow it to be changed dynamically.
Signed-off-by: NOtavio Salvador <otavio@ossystems.com.br>

include/configs/wandboard.h

@@ -78,7 +78,7 @@
 #endif
 
 #define CONFIG_EXTRA_ENV_SETTINGS \
-	"console=ttymxc0,115200\0" \
+	"console=ttymxc0\0" \
 	"splashpos=m,m\0" \
 	"fdtfile=undefined\0" \
 	"fdt_high=0xffffffff\0" \