cfg80211: use enum nl80211_dfs_regions for dfs_region everywhere

u8 was used in some other places, just stick to the enum,
this forces us to express the values that are expected.

Signed-off-by: Luis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/include/net/regulatory.h b/include/net/regulatory.h
index 92ab80f..c96a0b8 100644
--- a/include/net/regulatory.h
+++ b/include/net/regulatory.h
@@ -79,7 +79,7 @@
 	enum nl80211_reg_initiator initiator;
 	enum nl80211_user_reg_hint_type user_reg_hint_type;
 	char alpha2[2];
-	u8 dfs_region;
+	enum nl80211_dfs_regions dfs_region;
 	bool intersect;
 	bool processed;
 	enum environment_cap country_ie_env;
@@ -157,7 +157,7 @@
 	struct rcu_head rcu_head;
 	u32 n_reg_rules;
 	char alpha2[2];
-	u8 dfs_region;
+	enum nl80211_dfs_regions dfs_region;
 	struct ieee80211_reg_rule reg_rules[];
 };