ASoC: codecs: Check for error pointer after calling devm_regmap_init_mmio

ASoC: codecs: Check for error pointer after calling devm_regmap_init_mmio

Since the potential failure of the devm_regmap_init_mmio(), it will
return error pointer and be assigned to the regmap.
Then the error pointer will be dereferenced.
For example rx->regmap will be used in rx_macro_mclk_enable().
Therefore, it should be better to check it.

Fixes: 1ba900724425 ("ASoC: codecs: lpass-rx-macro: add support for lpass rx macro")
Fixes: b6280797a4e9 ("ASoC: codecs: lpass-tx-macro: add support for lpass tx macro")
Fixes: b7da356d54bc ("ASoC: codecs: lpass-wsa-macro: Add support to WSA Macro")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Link: https://lore.kernel.org/r/20220121171031.2826198-1-jiasheng@iscas.ac.cn
Signed-off-by: Mark Brown <broonie@kernel.org>