ASoC: sun8i-codec: fix crash on module removal

drvdata is actually sun8i_codec, not snd_soc_card, so it crashes
when calling snd_soc_card_get_drvdata().

Drop card and scodec vars anyway since we don't need to
disable/unprepare clocks - it's already done by calling
runtime_suspend()

Drop clk_disable_unprepare() calls for the same reason.

Fixes: 36c68493 ("ASoC: Add sun8i digital audio codec")
Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>