tests: cover PMU group inheritance across fork

[afscoelho_gmail.com]

Summary

Add deterministic ATF coverage for committed-group inheritance, descendant targeting, resident and evicted groups, concurrent target exit, cleanup, and failure rollback across fork.

Sponsored by: AMD

Signed-off-by: Andre Silva <[e-mail]>

[afscoelho_gmail.com]

Rebase onto main after D58256 landed. Update tests/sys/pmc/Makefile for the new tests in main.

[afscoelho_gmail.com]

Rebase only. No change.

[afscoelho_gmail.com]

Rebase on main (D60141 and D60185 are committed). No change.

[afscoelho_gmail.com]

Rebase only. No code change.