boards: ls2080: Fix default bootargs

A white space is missing in multiple-line string for bootargs.

Signed-off-by: York Sun <york.sun@nxp.com>
diff --git a/include/configs/ls2080ardb.h b/include/configs/ls2080ardb.h
index 14635b7..59a3f66 100644
--- a/include/configs/ls2080ardb.h
+++ b/include/configs/ls2080ardb.h
@@ -333,7 +333,7 @@
 
 #undef CONFIG_BOOTARGS
 #define CONFIG_BOOTARGS		"console=ttyS1,115200 root=/dev/ram0 " \
-				"earlycon=uart8250,mmio,0x21c0600" \
+				"earlycon=uart8250,mmio,0x21c0600 " \
 				"ramdisk_size=0x2000000 default_hugepagesz=2m" \
 				" hugepagesz=2m hugepages=256"