mac80211: start moving scan code from mlme

Here's a first patch to move some code from mlme.c to a
new file called scan.c. The end result will hopefully be
a more manageable mlme.c.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --cc net/mac80211/Makefile
Simple merge

diff --cc net/mac80211/ieee80211_i.h
Simple merge

diff --cc net/mac80211/mlme.c
Simple merge

diff --cc net/mac80211/scan.c
Simple merge