sound fixes for 4.13-rc8

Three regression fixes that should be addressed before the final
release: a missing mutex call in OSS PCM emulation ioctl, ASoC rt5670
headset detection breakage, and a regression in simple-card parser
code.
Merge tag 'asoc-fix-v4.13-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus

ASoC: Fixes for v4.13

A couple of fixes, one for a regression in simple-card introduced during
the merge window that was only reported this week and another for a
regression in registration of ACPI GPIOs.