drm/i915: Fix audio component initialization

After registering the audio component in i915_audio_component_init()
the audio driver may call i915_audio_component_get_power() via the
component ops. This could program AUD_FREQ_CNTRL with an uninitialized
value if the latter function is called before display.audio.freq_cntrl
gets initialized. The get_power() function also does a modeset which in
the above case happens too early before the initialization step and
triggers the

"Reject display access from task"

error message added by the Fixes: commit below.

Fix the above issue by registering the audio component only after the
initialization step.

Fixes: 87c16945

 ("drm/i915: save AUD_FREQ_CNTRL state at audio domain suspend")
Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/10291
Cc: stable@vger.kernel.org # v5.5+
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240521143022.3784539-1-imre.deak@intel.com
(cherry picked from commit fdd0b801

)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>