ASoC: txx9aclc_ac97: Fix kernel crash on probe

This patch fixes a crash caused by commit 3bed3344
(ASoC: txx9aclc_ac97: Convert to devm_ioremap_resource()).
This is an attempt to assign "drvdata->base" while memory
for "drvdata" is not already allocated.

Fixes: 3bed3344

 (ASoC: txx9aclc_ac97: Convert to devm_ioremap_resource())
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Mark Brown <broonie@linaro.org>
Cc: stable@vger.kernel.org