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

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: d33a54e3991d ("drm/probe_helper: sort out poll_running vs poll_enabled")
CC: [email protected] # 6.4+
Cc: Dmitry Baryshkov <[email protected]>
Cc: [email protected]
Reviewed-by: Jouni Högander <[email protected]>
Signed-off-by: Imre Deak <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
(cherry picked from commit 50452f2f76852322620b63e62922b85e955abe94)
Signed-off-by: Rodrigo Vivi <[email protected]>