cfg80211: fix WIPHY_FLAG_IBSS_RSN bit

WIPHY_FLAG_IBSS_RSN is BIT(7) as is WIPHY_FLAG_CONTROL_PORT_PROTOCOL. Change
to BIT(8).

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>