drm/i915/audio: Split "ELD valid" vs. audio PD on hsw+

On the older platforms the audio presence detect bit is in
the port register, so it gets written outside audio codec hooks
and is this separate from the ELD valid toggling. Split the
operations into two steps on hsw+ to be more consistent with
both the other platforms and the spec. Also according to the
spec we might need some vblank waits between the two which
definitely needs them done separately.

Cc: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
Cc: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Cc: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221026170150.2654-14-ville.syrjala@linux.intel.com