nl80211: vendor command support

Add support for vendor-specific commands to nl80211. This is
intended to be used for really vendor-specific functionality
that can't be implemented in a generic fashion for any reason.
It's *NOT* intended to be used for any normal/generic feature
or any optimisations that could be implemented across drivers.
Currently, only vendor commands (with replies) are supported,
no dump operations or vendor-specific notifications.
Also add a function wdev_to_ieee80211_vif() to mac80211 which
is needed for mac80211-based drivers wanting to implement any
vendor commands.

Change-Id: Ic4729180ea31b39e7313633f216a06b96a29ee39
CRs-fixed: 576020
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Git-commit: ad7e718c9b4f717823fd920a0103f7b0fb06183f
Git-repo: https://git.kernel.org/cgit/linux/kernel/git/linville/wireless-next.git
Signed-off-by: Leo Chang <leochang@codeaurora.org>
nl80211: Correct the usage of command NL80211_CMD_VENDOR

Assign/pass the cur_cmd_info parameter correctly. This fixes a
merge error when open source commit
ad7e718c9b4f717823fd920a0103f7b0fb06183f was pulled into the tree.

CRs-Fixed: 672390
Change-Id: Iaa21a1723709683a6f34b07423b74ef0b6077b68
Signed-off-by: Sunil Dutt <usdutt@codeaurora.org>
Enable NEED_NETDEV for vendor command support.

The Vendor command needs to have the NEED_NETDEV internal flag set
for the corresponding vendor_cmd function to initialize correctly
and call the vendor subcommand specific doit function.

CRs-fixed: 633799
Change-Id: Icc46438dc9467fe0344cb832633c49466e2d20d0
Signed-off-by: Subhani Shaik <subhanis@codeaurora.org>