ASoC: loongson: Fix component check failed on FDT systems

Add missing snd_soc_dai_link.platforms assignment to avoid
soc_dai_link_sanity_check() failure.

Fixes: d2402860 ("ASoC: loongson: Add Loongson ASoC Sound Card Support")
Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
Link: https://patch.msgid.link/6645888f2f9e8a1d8d799109f867d0f97fd78c58.1728459624.git.zhoubinbin@loongson.cn


Signed-off-by: Mark Brown <broonie@kernel.org>