bpf: add small subset of SECURITY_PATH hooks to BPF sleepable_lsm_hooks list

security_path_* based LSM hooks appear to be generally missing from
the sleepable_lsm_hooks list. Initially add a small subset of them to
the preexisting sleepable_lsm_hooks list so that sleepable BPF helpers
like bpf_d_path() can be used from sleepable BPF LSM based programs.

The security_path_* hooks added in this patch are similar to the
security_inode_* counterparts that already exist in the
sleepable_lsm_hooks list, and are called in roughly similar points and
contexts. Presumably, making them OK to be also annotated as
sleepable.

Building a kernel with DEBUG_ATOMIC_SLEEP options enabled and running
reasonable workloads stimulating activity that would be intercepted by
such security hooks didn't show any splats.

Notably, I haven't added all the security_path_* LSM hooks that are
available as I don't need them at this point in time.

Signed-off-by: Matt Bobrowski <mattbobrowski@google.com>
Acked-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/r/ZXM3IHHXpNY9y82a@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>