Merge branch 'bpf-fs-mount-options-parsing-follow-ups'

Andrii Nakryiko says:

====================
BPF FS mount options parsing follow ups

Original BPF token patch set ([0]) added delegate_xxx mount options which
supported only special "any" value and hexadecimal bitmask. This patch set
attempts to make specifying and inspecting these mount options more
human-friendly by supporting string constants matching corresponding bpf_cmd,
bpf_map_type, bpf_prog_type, and bpf_attach_type enumerators.

This implementation relies on BTF information to find all supported symbolic
names. If kernel wasn't built with BTF, BPF FS will still support "any" and
hex-based mask.

  [0] https://patchwork.kernel.org/project/netdevbpf/list/?series=805707&state=*

v1->v2:
  - strip BPF_, BPF_MAP_TYPE_, and BPF_PROG_TYPE_ prefixes,
    do case-insensitive comparison, normalize to lower case (Alexei).
====================

Link: https://lore.kernel.org/r/20231214225016.1209867-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>