staging: wlags49_h2: Fixup WEXT capabilities

Add recently added events to the capabilities reported in iw_range.
Use capability macros instead of assuming the array offsets.

Explicitly list scan capabilities.

Signed-off-by: David Kilroy <kilroyd@googlemail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>