qcacld-2.0: Fix monitor mode not showing in iwconfig and iw utility

iwconfig was showing interface type as managed in case of monitor mode

Added the support for NL80211_IFTYPE_MONITOR and IW_MODE_MONITOR in
the code

Change-Id: Ibde24dd3b826fc744d1ec82820fcb51952e1b6ef
CRs-Fixed: 2139968