drm/i915: Clean up gen3 hotplug irq setup

For the "always on/unmasked" interrupts we initialize
dev_priv->irq_mask first, then enable_mask. Follow the
same order for the hotplug interrupt so that things are
a bit less confusing.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240927143545.8665-3-ville.syrjala@linux.intel.com


Reviewed-by: Jani Nikula <jani.nikula@intel.com>