drm/i915/display: Remove fbdev suspend and hotplug tracking

drm/i915/display: Remove fbdev suspend and hotplug tracking

The DRM client code already tracks suspend status and hotplug events
for each client. Remove similar code from i915's fbdev client.

Allows for the removal of all hdp_* fields form struct intel_fbdev.
Calls to intel_fbdev_output_poll_changed() are reduced the shared
helper drm_fb_helper_hotplug_event().

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241212170913.185939-5-tzimmermann@suse.de
Signed-off-by: Maarten Lankhorst <dev@lankhorst.se>