ath9k: Fix p2p address management

When multiple channel contexts are enabled, a p2p interface
that is assigned to a context will have an address that
is different from the device mac address, which is used
by wpa_s as the p2p device ID.

Certain frames like provision requests use the device address
and these get dropped since ath9k_calculate_summary_state()
iterates over only the active interfaces in a context and the
device address is not used.

Fix this by adding the device mac address to the bssid mask.

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>