drm-legacy is broken, again

[Mark Johnston]

On Thu, Aug 01, 2019 at 12:10:09PM -0700, Steve Kargl wrote:
> Just updated /usr/src to top of tree.
> 
> Trying to update drm-legacy port.  After
> a failed 'make' in /usr/ports/drm-legacy

The patch below should fix it.  drm was relying on refcount.h including
limits.h.

diff --git a/src/dev/drm2/drmP.h b/src/dev/drm2/drmP.h
index 3af7ad1..7cbd8db 100644
--- a/src/dev/drm2/drmP.h
+++ b/src/dev/drm2/drmP.h
@@ -42,6 +42,7 @@ __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
 #include <sys/queue.h>
+#include <sys/limits.h>
 #include <sys/malloc.h>
 #include <sys/kernel.h>
 #include <sys/ktr.h>