backend/drm: add support for libliftoff v0.5.0

Don't require libliftoff 0.5.0 just yet: we want to be able to
backport this patch.

backend/drm/libliftoff.c

@@ -8,6 +8,7 @@
 #include "backend/drm/drm.h"
 #include "backend/drm/fb.h"
 #include "backend/drm/iface.h"
+#include "config.h"
 
 static bool init(struct wlr_drm_backend *drm) {
 	// TODO: lower log level
@@ -407,7 +408,11 @@ static bool commit(struct wlr_drm_backend *drm,
 		struct wlr_drm_connector *conn = state->connectors[i].connector;
 		struct wlr_drm_crtc *crtc = conn->crtc;
 
+#if HAVE_LIBLIFTOFF_0_5
+		int ret = liftoff_output_apply(crtc->liftoff, req, flags, NULL);
+#else
 		int ret = liftoff_output_apply(crtc->liftoff, req, flags);
+#endif
 		if (ret != 0) {
 			wlr_drm_conn_log(conn, test_only ? WLR_DEBUG : WLR_ERROR,
 				"liftoff_output_apply failed: %s", strerror(-ret));

backend/drm/meson.build

@@ -48,6 +48,7 @@ wlr_files += files(
 
 if libliftoff.found()
 	wlr_files += files('libliftoff.c')
+	internal_config.set10('HAVE_LIBLIFTOFF_0_5', libliftoff.version().version_compare('>=0.5.0'))
 endif
 
 features += { 'drm-backend': true }