drm/i2c/adv7511: Constify function pointer structs

Moves a bunch of junk to .rodata from .data.

 drivers/gpu/drm/i2c/adv7511.ko:
-.rodata                     1368
+.rodata                     1416
-.data                        164
+.data                        116
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450178476-26284-20-git-send-email-boris.brezillon@free-electrons.comSigned-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i2c/adv7511.c

@@ -752,7 +752,7 @@ static void adv7511_encoder_mode_set(struct drm_encoder *encoder,
 	adv7511->f_tmds = mode->clock;
 }
 
-static struct drm_encoder_slave_funcs adv7511_encoder_funcs = {
+static const struct drm_encoder_slave_funcs adv7511_encoder_funcs = {
 	.dpms = adv7511_encoder_dpms,
 	.mode_valid = adv7511_encoder_mode_valid,
 	.mode_set = adv7511_encoder_mode_set,