ASoC: uda1380: Replace direct snd_soc_codec dapm field access

ASoC: uda1380: Replace direct snd_soc_codec dapm field access

The dapm field of the snd_soc_codec struct is eventually going to be
removed, in preparation for this replace all manual access to
codec->dapm.bias_level with snd_soc_codec_get_bias_level().

Also drop the unnecessary check at the beginning of the
uda1380_set_bias_level() which compares the current level to the target
level and aborts if they are the same. Since the core will not call the
set_bias_level() callback if we already are in the target state the result
of the check is always false.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>