drm/i2c/tda998x: Remove unused save/restore drm encoder helpers.

save/restore have been removed from drm_encoder_helper_funcs by
'commit 79f13ad5d8e0 ("drm: Move encoder->save/restore into nouveau")'

But this module was still defining it with empty content causing
compilation fails:

drivers/gpu/drm/i2c/tda998x_drv.c:1354:10: warning: initialization from
incompatible pointer type [-Wincompatible-pointer-types]
  .save = tda998x_encoder_save,

drivers/gpu/drm/i2c/tda998x_drv.c:1355:2: error: unknown field 'restore'
specified in initializer
  .restore = tda998x_encoder_restore,

Cc: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449513306-17309-1-git-send-email-rodrigo.vivi@intel.com

drivers/gpu/drm/i2c/tda998x_drv.c

@@ -855,18 +855,6 @@ static void tda998x_encoder_dpms(struct drm_encoder *encoder, int mode)
 	priv->dpms = mode;
 }
 
-static void
-tda998x_encoder_save(struct drm_encoder *encoder)
-{
-	DBG("");
-}
-
-static void
-tda998x_encoder_restore(struct drm_encoder *encoder)
-{
-	DBG("");
-}
-
 static bool
 tda998x_encoder_mode_fixup(struct drm_encoder *encoder,
 			  const struct drm_display_mode *mode,
@@ -1351,8 +1339,6 @@ static void tda998x_encoder_commit(struct drm_encoder *encoder)
 
 static const struct drm_encoder_helper_funcs tda998x_encoder_helper_funcs = {
 	.dpms = tda998x_encoder_dpms,
-	.save = tda998x_encoder_save,
-	.restore = tda998x_encoder_restore,
 	.mode_fixup = tda998x_encoder_mode_fixup,
 	.prepare = tda998x_encoder_prepare,
 	.commit = tda998x_encoder_commit,