drm/i915: Fix HPD polling, reenabling the output poll work as needed

After the commit in the Fixes: line below, HPD polling stopped working
on i915, since after that change calling drm_kms_helper_poll_enable()
doesn't restart drm_mode_config::output_poll_work if the work was
stopped (no connectors needing polling) and enabling polling for a
connector (during runtime suspend or detecting an HPD IRQ storm).

After the above change calling drm_kms_helper_poll_enable() is a nop
after it's been called already and polling for some connectors was
disabled/re-enabled.

Fix this by calling drm_kms_helper_poll_reschedule() added in the
previous patch instead, which reschedules the work whenever expected.

Fixes: d33a54e3 ("drm/probe_helper: sort out poll_running vs poll_enabled")
CC: stable@vger.kernel.org # 6.4+
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Jouni Högander <jouni.hogander@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230822113015.41224-2-imre.deak@intel.com

drivers/gpu/drm/i915/display/intel_hotplug.c

@@ -212,7 +212,7 @@ intel_hpd_irq_storm_switch_to_polling(struct drm_i915_private *dev_priv)
 
 	/* Enable polling and queue hotplug re-enabling. */
 	if (hpd_disabled) {
-		drm_kms_helper_poll_enable(&dev_priv->drm);
+		drm_kms_helper_poll_reschedule(&dev_priv->drm);
 		mod_delayed_work(dev_priv->unordered_wq,
 				 &dev_priv->display.hotplug.reenable_work,
 				 msecs_to_jiffies(HPD_STORM_REENABLE_DELAY));
@@ -727,7 +727,7 @@ static void i915_hpd_poll_init_work(struct work_struct *work)
 	drm_connector_list_iter_end(&conn_iter);
 
 	if (enabled)
-		drm_kms_helper_poll_enable(&dev_priv->drm);
+		drm_kms_helper_poll_reschedule(&dev_priv->drm);
 
 	mutex_unlock(&dev_priv->drm.mode_config.mutex);