In order to later add tracing or verifications to the driver
calls mac80211 makes, this patch adds static inline wrappers
for all operations.

All calls are now written as

	drv_<op>(local, ...);

instead of

	local->ops-><op>(&local->hw, ...);

Where necessary, the wrappers also do existence checking and
return default values as appropriate.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>