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/net/wireless/reg.c b/net/wireless/reg.c
index 067c1f6..2796b62 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -2115,7 +2115,7 @@
 	}
 }
 
-bool reg_supported_dfs_region(u8 dfs_region)
+bool reg_supported_dfs_region(enum nl80211_dfs_regions dfs_region)
 {
 	switch (dfs_region) {
 	case NL80211_DFS_UNSET:
@@ -2130,7 +2130,7 @@
 	}
 }
 
-static void print_dfs_region(u8 dfs_region)
+static void print_dfs_region(enum nl80211_dfs_regions dfs_region)
 {
 	if (!dfs_region)
 		return;