tests/kms-steal-crtc: Use correct includes

It was relying on drm_fourcc.h providing <stdint.h>, which is silly.
Fix it.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
diff --git a/tests/kms/kms-steal-crtc.c b/tests/kms/kms-steal-crtc.c
index 497772e..4b830d2 100644
--- a/tests/kms/kms-steal-crtc.c
+++ b/tests/kms/kms-steal-crtc.c
@@ -29,6 +29,7 @@
 #include <fcntl.h>
 #include <signal.h>
 #include <stdio.h>
+#include <stdint.h>
 #include <string.h>
 #include <unistd.h>
 #ifdef HAVE_SYS_SELECT_H