Move from memcpy to memcpy_s.

Change-Id: If7d53c6e54428f01f14528c3f281331d308af56a
diff --git a/src/fdt_handler.c b/src/fdt_handler.c
index 0a0b294..8d701ee 100644
--- a/src/fdt_handler.c
+++ b/src/fdt_handler.c
@@ -35,7 +35,7 @@
 	case sizeof(uint32_t):
 		return be32toh(*(uint32_t *)data);
 	case sizeof(uint64_t):
-		memcpy(t.a, data, sizeof(uint64_t));
+		memcpy_s(t.a, sizeof(t.a), data, sizeof(uint64_t));
 		return be64toh(t.v);
 	default:
 		return 0;
@@ -86,7 +86,7 @@
 
 	case sizeof(uint64_t):
 		t.v = be64toh(value);
-		memcpy((void *)data, t.a, sizeof(uint64_t));
+		memcpy_s((void *)data, size, t.a, sizeof(uint64_t));
 		break;
 
 	default: