ASoC: codecs: pm4125: clean up bind() device reference handling

ASoC: codecs: pm4125: clean up bind() device reference handling

A recent change fixed a couple of device leaks on component bind failure
and on unbind but did so in a confusing way by adding misleading
initialisations at bind() and bogus NULL checks at unbind().

Cc: Ma Ke <make24@iscas.ac.cn>
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://patch.msgid.link/20251219142412.19043-1-johan@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>