Merge branch 'bpf: Add hwtstamp field for the sockops prog'

Merge branch 'bpf: Add hwtstamp field for the sockops prog'

Martin KaFai Lau says:

====================

From: Martin KaFai Lau <martin.lau@kernel.org>

The bpf-tc prog has already been able to access the
skb_hwtstamps(skb)->hwtstamp.  This set extends the same hwtstamp
access to the sockops prog.

v2:
- Fixed the btf_dump selftest which depends on the
  last member of 'struct bpf_sock_ops'.
====================

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>