ASoC: simple-card: fix probe failure on platform component

ASoC: simple-card: fix probe failure on platform component

A previous change to simple-card resulted in asoc_simple_parse_dai
attempting to retrieve the dai_name for platform components, which are
unlikely to have a valid DAI name. This caused simple-card to fail to
probe when using the xlnx_formatter_pcm as the platform component, since
it does not register any DAI components.

Since the dai_name is not used for platform components, just skip trying
to retrieve it for those.

Fixes: f107294c6422 ("ASoC: simple-card: support snd_soc_dai_link_component style for cpu")
Signed-off-by: Robert Hancock <robert.hancock@calian.com>
Link: https://lore.kernel.org/r/20220107214711.1100162-6-robert.hancock@calian.com
Signed-off-by: Mark Brown <broonie@kernel.org>