mwl8787: fix busted ht40 flag assignment.

Thomas pointed out this silly error.

Signed-off-by: Bob Copeland <me@bobcopeland.com>
mwl8787: fix direction of this bit conversion

Signed-off-by: Bob Copeland <me@bobcopeland.com>
mwl8787: drop this extra bitwise conversion

Sparse rightly complained; left over from when I was comparing
the un-converted hdr->type.

Signed-off-by: Bob Copeland <me@bobcopeland.com>
mwl8787: rename mcs fields to be more obvious

dev_mcs_support is 0x11 for 1x1, 0x22 for 2x2, etc.  We
assume that #streams = rx chains as before.  Rename the
fields accordingly.

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