CVE-2021-47502

In the Linux kernel, the following vulnerability has been resolved: ASoC:
codecs: wcd934x: handle channel mappping list correctly Currently each
channel is added as list to dai channel list, however there is danger of
adding same channel to multiple dai channel list which endups corrupting
the other list where its already added. This patch ensures that the channel
is actually free before adding to the dai channel list and also ensures
that the channel is on the list before deleting it. This check was missing
previously, and we did not hit this issue as we were testing very simple
usecases with sequence of amixer commands.