wil6210: propagate disconnect reason

Propagate reason for the disconnect through the relevant call chains:
- report to cfg80211 reason as reported by the firmware
- provide to the firmware reason as requested by cfg80211

Change-Id: I3f2f65ddb862968badec839db60d5b8ec1f4efeb
Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Git-commit: 4821e6d8770087278286220e36d219474854f1f5
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-testing.git


[hkadmany@codeaurora.org: trivial backport to kernel 3.10]
Signed-off-by: Hamad Kadmany <hkadmany@codeaurora.org>