Bump __FreeBSD_version for sound(4) KPI changes

[christos]

Summary

Bump __FreeBSD_version for sound(4) KPI changes

516a9c0212b0 ("sound: Make device registration more intuitive")
introduced changes to the device registration KPI which break unpatched
out-of-tree drivers.

More specifically, up until 516a9c0212b0, drivers would usually register
a device as follows:

• pcm_register(dev, softc, playchans, recchans)
• pcm_addchan(...)
• pcm_setstatus(dev, statustr)

Drivers now should register as follows:

• pcm_init(dev, softc)
• pcm_addchan(...)
• pcm_register(dev, statustr)

Essentially, to patch a driver to use the new KPI:

1. Use pcm_init() in place of pcm_register(), and remove return value checks, as pcm_init() is void.
2. Use pcm_register() in place of pcm_setstatus() and _do_ check for the return value.

Sponsored by: The FreeBSD Foundation
MFC after: 2 days

[markj]

sys/sys/param.h

76

This is out of date (current value is 1500026), but yes the change is fine.

The commit message should describe in more detail what changed, so that it's easier for maintainers to update their code.

[christos]

Use correct version value.

[markj]

Someone else just bumped FreeBSD_version to 1500027, so I would suggest piggy-backing off of that. That is, there's no need to bump FreeBSD_version again; just use 1500027 as the guard.

On stable/14, I suspect that the change should be reverted to avoid breaking the cx88 port.

[imp]

I'd piggyback...

[emaste]

These values are documented in the porters handbook https://docs.freebsd.org/en/books/porters-handbook/versions/
I don't see 1500027 there yet, but we will want to have it mention both changes.

[christos]

Abandoning since __FreeBSD_version was bumped already. Also reverted KPI changes for stable/14: https://cgit.freebsd.org/src/commit/?h=stable/14&id=b64867e332f8196cb61947fc189ff108ca1065db