drm/i915: fix VDD state tracking after system resume

Just like during booting the BIOS can leave the VDD bit enabled after
system resume. So apply the same state sanitization there too. This
fixes a problem where after resume the port power domain refcount gets
unbalanced.

v2:
- unchanged
v3:
- call edp sanitizing from the encoder reset handler (Daniel)

Reported-and-tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_dp.c

@@ -4002,6 +4002,11 @@ void intel_dp_encoder_destroy(struct drm_encoder *encoder)
 	kfree(intel_dig_port);
 }
 
+static void intel_dp_encoder_reset(struct drm_encoder *encoder)
+{
+	intel_edp_panel_vdd_sanitize(to_intel_encoder(encoder));
+}
+
 static const struct drm_connector_funcs intel_dp_connector_funcs = {
 	.dpms = intel_connector_dpms,
 	.detect = intel_dp_detect,
@@ -4017,6 +4022,7 @@ static const struct drm_connector_helper_funcs intel_dp_connector_helper_funcs =
 };
 
 static const struct drm_encoder_funcs intel_dp_enc_funcs = {
+	.reset = intel_dp_encoder_reset,
 	.destroy = intel_dp_encoder_destroy,
 };