ASoC: tas2552: Fix kernel crash when the codec is loaded but not part of a card

[ Upstream commit 80ba2669ec8c3e6517aa935001f6cb8809bf3df4 ]

If the card is not part of any card the tas_data->codec is NULL since it is
set only during snd_soc_codec_driver.probe, which is not yet called.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>