LinuxKPI: 802.11: fill regulatory_hint() with some life

Start implementing regulatory_hint() using a .c file based allocation
helper function so we could change structures in the future with
better chances to keep compatibility.
This sets wiphy->regd needed by various LinuxKPI based WiFi drivers.

Sponsored by:	The FreeBSD Foundation
MFC after:	3 days

sys/compat/linuxkpi/common/include/net/cfg80211.h

@@ -1260,6 +1260,8 @@ struct cfg80211_bss *linuxkpi_cfg80211_get_bss(struct wiphy *,
     const uint8_t *, size_t, enum ieee80211_bss_type, enum ieee80211_privacy);
 void linuxkpi_cfg80211_put_bss(struct wiphy *, struct cfg80211_bss *);
 void linuxkpi_cfg80211_bss_flush(struct wiphy *);
+struct linuxkpi_ieee80211_regdomain *
+    lkpi_get_linuxkpi_ieee80211_regdomain(size_t);
 
 /* -------------------------------------------------------------------------- */
 
@@ -1587,8 +1589,22 @@ regulatory_set_wiphy_regd(struct wiphy *wiphy,
 static __inline int
 regulatory_hint(struct wiphy *wiphy, const uint8_t *alpha2)
 {
-	TODO();
-	return (-ENXIO);
+	struct linuxkpi_ieee80211_regdomain *regd;
+
+	if (wiphy->regd != NULL)
+		return (-EBUSY);
+
+	regd = lkpi_get_linuxkpi_ieee80211_regdomain(0);
+	if (regd == NULL)
+		return (-ENOMEM);
+
+	regd->alpha2[0] = alpha2[0];
+	regd->alpha2[1] = alpha2[1];
+	wiphy->regd = regd;
+
+	IMPROVE("are there flags who is managing? update net8011?");
+
+	return (0);
 }
 
 static __inline const char *

sys/compat/linuxkpi/common/src/linux_80211.c

@@ -4028,6 +4028,16 @@ linuxkpi_ieee80211_iterate_stations_atomic(struct ieee80211_hw *hw,
 	LKPI_80211_LHW_LVIF_UNLOCK(lhw);
 }
 
+struct linuxkpi_ieee80211_regdomain *
+lkpi_get_linuxkpi_ieee80211_regdomain(size_t n)
+{
+	struct linuxkpi_ieee80211_regdomain *regd;
+
+	regd = kzalloc(sizeof(*regd) + n * sizeof(struct ieee80211_reg_rule),
+	    GFP_KERNEL);
+	return (regd);
+}
+
 int
 linuxkpi_regulatory_set_wiphy_regd_sync(struct wiphy *wiphy,
     struct linuxkpi_ieee80211_regdomain *regd)