mac80211: fix led behavior in IBSS

This patch fixes the led behavior in IBSS. After we joined an IBSS cell we
need to inform the led that we got associated. Although there is no 802.11
association in IBSS mode, the semantic of "There is a link" is relevant.
This allows the led to blink in IBSS mode (at least this solves a bug for
iwlwifi).

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Reviewed-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>