ls1088a: Add missing headers to eth_ls1088aqds.c

As we call sprintf in this file we need to include vsprintf.h in order
to get the function prototype and we need linux/string.h for strcmp.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/board/freescale/ls1088a/eth_ls1088aqds.c b/board/freescale/ls1088a/eth_ls1088aqds.c
index f62f5fd..2fece3a 100644
--- a/board/freescale/ls1088a/eth_ls1088aqds.c
+++ b/board/freescale/ls1088a/eth_ls1088aqds.c
@@ -3,6 +3,8 @@
  * Copyright 2017 NXP
  */
 
+#include <vsprintf.h>
+#include <linux/string.h>
 #include <asm/io.h>
 #include <asm/arch/fsl_serdes.h>
 #include <fsl-mc/fsl_mc.h>