CNB: genetlink: support per op type policies

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2175250
Depends: https://bugzilla.redhat.com/show_bug.cgi?id=2175249
Tested: LNST net driver test-suite on bnxt_en, i40e, ice, mlx5_core, sfc and devlink self-tests

Commits:

249801360db3 ("net: genl: fix error path memory leak in policy dumping")
a1a824f448ba ("genetlink: fix kdoc warnings")
ff14adbd8779 ("genetlink: refactor the cmd <> policy mapping dump")
7c3eaa022261 ("genetlink: move the private fields in struct genl_family")
20b0b53aca43 ("genetlink: introduce split op representation")
7747eb75f618 ("genetlink: load policy based on validation flags")
e1a248911d06 ("genetlink: check for callback type at op load time")
92d3d9ba9bb3 ("genetlink: add policies for both doit and dumpit in ctrl_dumppolicy_start()")
26588edbef60 ("genetlink: support split policies in ctrl_dumppolicy_put_op()")
8d84322ae6d7 ("genetlink: inline genl_get_cmd()")
6557461cd278 ("genetlink: add iterator for walking family ops")
b502b3185cd6 ("genetlink: use iterator in the op to policy map dumping")
7acfbbe17c18 ("genetlink: inline old iteration helpers")
b8fd60c36a44 ("genetlink: allow families to use split ops directly")
aba22ca8ccd6 ("genetlink: convert control family to split ops")
c1b05105573b ("genetlink: fix single op policy dump when do is present")
154ba79c9f16 ("genetlink: correctly begin the iteration over policies")

Signed-off-by: Ivan Vecera ivecera@redhat.com