wl1271: add support for HW TX fragmentation

Indicate to mac80211 we support HW fragmentation.
Support updates of the fragmentation threshold via the
set_frag_threshold callback.

Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: Luciano Coelho <luciano.coelho@nokia.com>
4 files changed