drm/display: Update comment on hdmi hotplug helper

Update the comment on drm_atomic_helper_connector_hdmi_hotplug() to
clarify that it must be called for all status updates.

Signed-off-by: David Turner <david.turner@raspberrypi.com>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20250317-vc4_hotplug-v4-1-2af625629186@raspberrypi.com


Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>