QCA vendor command for getting STA information

QCA vendor command for getting STA information

Add a QCA vendor subcommand QCA_NL80211_VENDOR_SUBCMD_GET_STA_INFO with
attributes defined in enum qca_wlan_vendor_attr_get_sta to get
information for a BSS in STA mode or for a peer STA in AP mode. This
vendor sub command can be used to get STA information from the driver to
userspace. The attributes defined in enum
qca_wlan_vendor_attr_get_sta_info are used to encapsulate required
information.

Signed-off-by: Min Liu <minliu@codeaurora.org>