nl80211: reduce non-split wiphy dump size

nl80211: reduce non-split wiphy dump size

When wiphy dumps cannot be split, such as in events or with
older userspace that doesn't support it, the size can today
be too big.

Reduce it, by doing two things:

 1) remove data that couldn't have been present before the
    split capability was introduced since it's new, such as
    HE capabilities

 2) as suggested by Martin Willi, remove management frame
    subtypes from the split dumps, as just (1) isn't even
    enough due to other new code capabilities. This is fine
    as old consumers (really just wpa_supplicant) didn't
    check this data before they got support for split dumps.

Reported-by: Martin Willi <martin@strongswan.org>
Suggested-by: Martin Willi <martin@strongswan.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Tested-by: Martin Willi <martin@strongswan.org>
Link: https://lore.kernel.org/r/20200928130655.53bce7873164.I71f06c9a221cd0630429a1a56eeae68a13beca61@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>