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/libweston/gl-renderer.h b/libweston/gl-renderer.h
index ad81a64..37d000f 100644
--- a/libweston/gl-renderer.h
+++ b/libweston/gl-renderer.h
@@ -25,6 +25,8 @@
 
 #include "config.h"
 
+#include <stdint.h>
+
 #include "compositor.h"
 
 #ifdef ENABLE_EGL