Fix order of #includes

This fix modifies the order of system includes to meet the ARM TF coding
standard whilst retaining header groupings.

Change-Id: Ib91968f8e2cac9e96033d73d3ad9d0a2ae228b13
Signed-off-by: Isla Mitchell <isla.mitchell@arm.com>
diff --git a/tools/fiptool/fiptool.c b/tools/fiptool/fiptool.c
index 65e4a25..4d80f2f 100644
--- a/tools/fiptool/fiptool.c
+++ b/tools/fiptool/fiptool.c
@@ -19,6 +19,7 @@
 #include <unistd.h>
 
 #include <openssl/sha.h>
+
 #include <firmware_image_package.h>
 
 #include "fiptool.h"