cfg80211: rename regulatory_hint_11d() to regulatory_hint_country_ie()

It is incorrect to refer to this as 11d as 802.11d was just a
proposed amendment, 802.11d was merged to the standard so
use proper terminology.

Signed-off-by: Luis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>