mwl8787: tell mac80211 we do connection monitoring

This is a bit of a lie at the moment -- the firmware can do it
but I don't believe we are set up to get the events.  However,
beacon RX is broken for stations currently so using STA mode
results in disconnect after 8 missed beacons and failed nullfunc
probe.

Signed-off-by: Bob Copeland <me@bobcopeland.com>
mwl8787: add rx a-mpdu

This allows other stations to set up ba/a-mpdu sessions with
us.  Testing with ath9k showed a 2x improvement in the RX
direction.

Signed-off-by: Bob Copeland <me@bobcopeland.com>
mwl8787: drop superfluous check

mp_wr_bitmap is initialized to all ones, and curr_wr_port should
be less than MWL8787_DATA_PORT_MASK.  So there's no case where
this will fail that won't already return -EBUSY.

Signed-off-by: Bob Copeland <me@bobcopeland.com>
mwl8787: clean up sdio tx code

Until now I barely understood what the sdio aggr code
was doing, so I rewrote it to make sense and cut out
some cruft.  Hopefully the result is more obvious; same
changes should be made for RX path.

Signed-off-by: Bob Copeland <me@bobcopeland.com>