Merge branch 'net-define-new-hwtstamp-flag-and-return-it-to-userspace'

Hangbin Liu says:

====================
net: define new hwtstamp flag and return it to userspace

This patchset defined the new hwtstamp flag HWTSTAMP_FLAG_BONDED_PHC_INDEX
to make userspace program build pass with old kernel header by settting ifdef.

Let's also return the flag when do SIOC[G/S]HWTSTAMP to let userspace know
that it's necessary for a given netdev.
====================

Link: https://lore.kernel.org/r/20211229080938.231324-1-liuhangbin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>