bpf: Enable sleeptable support for cgrp local storage

Similar to sk/inode/task local storage, enable sleepable support for
cgrp local storage.

Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221201050444.2785007-1-yhs@fb.com


Signed-off-by: Alexei Starovoitov <ast@kernel.org>