The osif request allocated in wlan_cfg80211_coap_cache_get_cbk()
is not freed for cases other than completed case, which will
result in memory leak in those cases.
To fix it, free osif request for all the cases.
Change-Id: I17998d0fb39e75b8b5f52a26d351056222c95536
CRs-Fixed: 3275889
Add os if layer for CoAP(Constrained Application Protocol)
component. It provides interfaces to parse netlink messages
for vendor command QCA_NL80211_VENDOR_SUBCMD_COAP_OFFLOAD
and take action accordingly, including enable/disable offload
reply/periodic transmitting for CoAP messages, and fetching
CoAP messages those cached during offload processing.
Change-Id: Ibbf9baf3802d305f9989e024ce764a6071b1fc6b
CRs-Fixed: 3254541
