Increase max scan IEs to allow big probe-req frames

Report a correct max-length for the scan IEs we can support, according
to the now larger size of the probe-req template.
Signed-off-by: NIdo Reis <idor@ti.com>
Signed-off-by: NArik Nemtsov <arik@wizery.com>
Signed-off-by: NEliad Peller <eliad@wizery.com>
Signed-off-by: NLuciano Coelho <coelho@ti.com>