qcacmn: Add a new QCA vendor attribute to configure wifi calling (wfc) state

Add QCA_WLAN_VENDOR_ATTR_CONFIG_WFC_STATE vendor attribute,
Userspace uses this attribute to configure wfc state to
Driver/Firmware. The Driver/Firmware uses this information to
optimize power savings, rate adaption, roaming, etc.

Change-Id: If58bd1e64216de81af6cf82eaabd740b85729eac
CRs-Fixed: 3343034