Apple Silicon audio moves to shared GPIO for Linux 7.4

Sources: Phoronix
Summary: Every speaker codec on Apple Silicon Macs has its software shutdown pin wired to the same GPIO line, so the first codec to change state decided it for the rest and later codecs were already off when their register state was cached, which made suspend and resume unworkable. Downstream Asahi used the regulator API as a proxy that deasserts only once every consumer agrees, and the kernel's shared GPIO infrastructure removes the need for that. The series also flips the TAS2764 and TAS2770 drivers to initialise the line low so the first transition establishes the intended default.
Why it matters: The work is queued in the Apple SoC driver branch for Linux 7.4, so mainline suspend and resume on these machines is fixed only from that release.
Follow-up: Confirm the series lands in the Linux 7.4 merge window.