cfg80211: fix n_reg_rules to match world_regdom

There are currently 8 rules in the world_regdom, but only the first 6
are applied due to an incorrect value for n_reg_rules.  This causes
channels 149-165 and 60GHz to be disabled.

Signed-off-by: Jason Abele <jason@aether.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>