drm/vc4: Mark the device as active when enabling runtime PM.

Failing to do so meant that we got a resume() callback on first use of
the device, so we would leak the bin BO that we allocated during
probe.

Signed-off-by: Eric Anholt <eric@anholt.net>
Fixes: 553c942 ("drm/vc4: Allow using more than 256MB of CMA memory.")
Link: http://patchwork.freedesktop.org/patch/msgid/20170515171615.10168-1-eric@anholt.net
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>

drivers/gpu/drm/vc4/vc4_v3d.c

@@ -401,6 +401,7 @@ static int vc4_v3d_bind(struct device *dev, struct device *master, void *data)
 		return ret;
 	}
 
+	pm_runtime_set_active(dev);
 	pm_runtime_use_autosuspend(dev);
 	pm_runtime_set_autosuspend_delay(dev, 40); /* a little over 2 frames. */
 	pm_runtime_enable(dev);