bpf, doc: add entries of who looks over which jits

bpf, doc: add entries of who looks over which jits

Make the high-level BPF JIT entry a general 'catch-all' and add
architecture specific entries to make it more clear who actively
maintains which BPF JIT compiler. The list (L) address implies
that this eventually lands in the bpf patchwork bucket. Goal is
that this set of responsible developers listed here is always up
to date and a point of contact for helping out in e.g. feature
development, fixes, review or testing patches in order to help
long-term in ensuring quality of the BPF JITs and therefore BPF
core under a given architecture. Every new JIT in future /must/
have an entry here as well.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Sandipan Das <sandipan@linux.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Zi Shen Lim <zlim.lnx@gmail.com>
Acked-by: Paul Burton <paul.burton@mips.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Wang YanQing <udknight@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>