include stdint.h for int32_t/uint32_t

Signed-off-by: Jussi Kukkonen <jussi.kukkonen@intel.com>
Reviewed-by: Yong Bakos <ybakos@humanoriented.com>
diff --git a/tests/keyboard-test.c b/tests/keyboard-test.c
index 9cf69ec..6b4ba19 100644
--- a/tests/keyboard-test.c
+++ b/tests/keyboard-test.c
@@ -25,6 +25,8 @@
 
 #include "config.h"
 
+#include <stdint.h>
+
 #include "weston-test-client-helper.h"
 
 TEST(simple_keyboard_test)