Add IPV4 in NUC472 target

Author: cyliangtw

hal/targets/cmsis/TARGET_NUVOTON/TARGET_NUC472/TARGET_NUMAKER_PFM_NUC472/TOOLCHAIN_GCC_ARM/NUC472.ld

@@ -237,7 +237,7 @@ SECTIONS
          */
         *lwip_*.o(.bss*)
         *lwip_*.o(COMMON)
-        __bss_extern_end__ = .;
+       __bss_extern_end__ = .;
     } > RAM_EXTERN
 
     .bss (NOLOAD):