wifihal: Fix dropping of generic nlmsgs from event sock

generic nlmsgs of cmd type pumac, log and cnss diag are
dropped as the cld80211 attribute is not present in the
nlmsg. This attribute is expected for target with cld80211
msg support only, hence generic nlmsg can be processed
further to extract packet info

CRs-Fixed: 2716646
Change-Id: I5c971ae9cbb57503a27a9720572b471960928c01