iw: fix HT PHY BSS Membership selector value encoding
iw: fix HT PHY BSS Membership selector value encoding

IEEE 802.11n 7.3.2.2 extended the supported rate IE to
support a special encoding for HT rate support.

iw needs to be updated in order to recognize
the magic value and parse it accordingly.

e.g.:

> Extended supported rates: 63.5*

now becomes:

> Extended supported rates: HT*

Signed-off-by: Christian Lamparter <2b86d4915b352c348b09e5d907edf5d041a1585c@googlemail.com>

timduru/platform-external-iw,TeamEOS/external_iw,cozybit/iw,TeamEOS/external_iw,SoluMachines/external_iw,Distrotech/iw,CTU-IIG/802.11p-iw,CTU-IIG/802.11p-iw,chunyeow/iw,Distrotech/iw,greearb/iw-ct,bw-oss/iw,OSLL/iw,greearb/iw-ct,bw-oss/iw,chunyeow/iw,cozybit/iw,timduru/platform-external-iw,SoluMachines/external_iw,OSLL/iw