cfg80211: fix NAN bands definition

The nl80211_nan_dual_band_conf enumeration doesn't make much sense.
The default value is assigned to a bit, which makes it weird if the
default bit and other bits are set at the same time.

To improve this, get rid of NL80211_NAN_BAND_DEFAULT and add a wiphy
configuration to let the drivers define which bands are supported.
This is exposed to the userspace, which then can make a decision on
which band(s) to use.  Additionally, rename all "dual_band" elements
to "bands", to make things clearer.

Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/trace.h

@@ -1736,21 +1736,21 @@ TRACE_EVENT(drv_start_nan,
 		LOCAL_ENTRY
 		VIF_ENTRY
 		__field(u8, master_pref)
-		__field(u8, dual)
+		__field(u8, bands)
 	),
 
 	TP_fast_assign(
 		LOCAL_ASSIGN;
 		VIF_ASSIGN;
 		__entry->master_pref = conf->master_pref;
-		__entry->dual = conf->dual;
+		__entry->bands = conf->bands;
 	),
 
 	TP_printk(
 		LOCAL_PR_FMT  VIF_PR_FMT
-		", master preference: %u, dual: %d",
+		", master preference: %u, bands: 0x%0x",
 		LOCAL_PR_ARG, VIF_PR_ARG, __entry->master_pref,
-		__entry->dual
+		__entry->bands
 	)
 );
 
@@ -1787,7 +1787,7 @@ TRACE_EVENT(drv_nan_change_conf,
 		LOCAL_ENTRY
 		VIF_ENTRY
 		__field(u8, master_pref)
-		__field(u8, dual)
+		__field(u8, bands)
 		__field(u32, changes)
 	),
 
@@ -1795,15 +1795,15 @@ TRACE_EVENT(drv_nan_change_conf,
 		LOCAL_ASSIGN;
 		VIF_ASSIGN;
 		__entry->master_pref = conf->master_pref;
-		__entry->dual = conf->dual;
+		__entry->bands = conf->bands;
 		__entry->changes = changes;
 	),
 
 	TP_printk(
 		LOCAL_PR_FMT  VIF_PR_FMT
-		", master preference: %u, dual: %d, changes: 0x%x",
+		", master preference: %u, bands: 0x%0x, changes: 0x%x",
 		LOCAL_PR_ARG, VIF_PR_ARG, __entry->master_pref,
-		__entry->dual, __entry->changes
+		__entry->bands, __entry->changes
 	)
 );