When update rate info to vdev mlme_priv, if in current assocrsp
there is no extend rate or mcs rate, need to clear such info.
otherwise such info is still last connection information.
the link rate will display wrongly, test step as:
1 connect with 11g AP
2 config AP to 11b, then connect manually
3 link speed will be wrong on sta side
if extend rate or mcs rate is not present, clear ext_opr_rate_set
and mcs_rate_set.
Change-Id: I8ff1b5804dbbe463d6949d0431079174446c64ad
CRs-Fixed: 3356077
bf0462e93e