nl80211/cfg80211: add max_sched_scan_ie_len in the hw description
Some chips may support different lengths of user-supplied IEs with a
single scheduled scan command than with a single normal scan command.
To support this, this patch creates a separate hardware description
element that describes the maximum size of user-supplied information
element data supported in scheduled scans.
Signed-off-by: Luciano Coelho <coelho@ti.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>