[RFC] sound: add uevent notifications for jack events

[Cryolitia PukNgae <cryolitia.pukngae@linux.dev>]

I propose adding uevent notifications for all audio jack events in the
sound subsystem, including headphone and microphone jacks.

The kernel already sends uevents for certain jack types like HDMI,
demonstrating this pattern is well-established. However, other common
audio jacks like headphones and microphones only generate input events,
not uevents.

This inconsistency affects userspace tools that rely on uevents for
device management. Adding uevents for all jack types would provide a
uniform interface for monitoring audio connection state changes.

My proposal is straightforward: extend the existing uevent mechanism to
cover all audio jack plug/unplug events in the sound subsystem. This
change would maintain backward compatibility with existing input event
consumers while providing consistent device notification for all jack
types.

The change aligns with the semantic purpose of uvents - to notify about
hardware state changes. Physical connection events naturally fit this
category.

If there are objections or historical context I should consider, I would
appreciate hearing them.

Thanks.

Best regards,
Cryolitia PukNgae