wil6210: fix disconnect handling for AP

For the AP-like interface, if "disconnect all" requested,
every station should be deleted with cfg80211_del_sta().
Implement this behavior.

Change-Id: I6a2a9c9522823426a6c39916bac59165fec521bc
Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Git-commit: fc58f6811a9edae55f64538bd361945572c366f6
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-testing.git


Signed-off-by: Hamad Kadmany <hkadmany@codeaurora.org>