drm/i915: constify intel_dvo_dev_ops structures

The intel_dvo_dev_ops structures are never modified, so declare them as
const.

Done with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1449608127-21715-1-git-send-email-Julia.Lawall@lip6.fr
diff --git a/drivers/gpu/drm/i915/dvo_ns2501.c b/drivers/gpu/drm/i915/dvo_ns2501.c
index 063859f..2379c33 100644
--- a/drivers/gpu/drm/i915/dvo_ns2501.c
+++ b/drivers/gpu/drm/i915/dvo_ns2501.c
@@ -698,7 +698,7 @@
 	}
 }
 
-struct intel_dvo_dev_ops ns2501_ops = {
+const struct intel_dvo_dev_ops ns2501_ops = {
 	.init = ns2501_init,
 	.detect = ns2501_detect,
 	.mode_valid = ns2501_mode_valid,