nl80211: add scan width to bss and scan request structs

To allow scanning and working with 5 MHz and 10 MHz BSS, extend the
inform bss commands and add wrappers to take 5 and 10 MHz bss into
account.

CRs-Fixed: 659678
Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Git-commit: dcd6eac1f3b5fa1df11dfa99da0cf75b76cfef97
Git-repo : http://git.kernel.org/cgit/linux/kernel/git/linville/wireless-next.git


[clanctot@codeaurora.org: Only picked up the add of NL80211_BSS_CHAN_WIDTH]
Change-Id: I684a1ad12e8b5cfe4c20f0fe549658cff22aaede
Signed-off-by: Chet Lanctot <clanctot@codeaurora.org>