qcacmn: Deregister NL MSG handlers during hdd_wlan_exit

Currently the NL MSG handlers for WLAN_NL_MSG_CNSS_DIAG, ANI_NL_MSG_PUMAC
and ANI_NL_MSG_PTT are not deregistered during hdd_wlan_exit which can
causes a page fault if NL issues cld80211_doit for these NL messages
when the WLAN is not up.

Add Deregsiter APIs for all the NL MSGs to call as part of
hdd_exit_netlink_services during hdd_wlan_exit.

Change-Id: I231e2f32e708e9a14305f0a8f9f2f603aa42b031
CRs-Fixed: 2243993