ASoC: qcom: sc7280: Fix missing Soundwire runtime stream alloc

In the Linux kernel, the following vulnerability has been resolved:

ASoC: qcom: sc7280: Fix missing Soundwire runtime stream alloc

Commit 15c7fab0e047 ("ASoC: qcom: Move Soundwire runtime stream alloc to

soundcards") moved the allocation of Soundwire stream runtime from the

Qualcomm Soundwire driver to each individual machine sound card driver,

except that it forgot to update SC7280 card.

Just like for other Qualcomm sound cards using Soundwire, the card

driver should allocate and release the runtime. Otherwise sound

playback will result in a NULL pointer dereference or other effect of

uninitialized memory accesses (which was confirmed on SDM845 having

similar issue).