Restore hostapd dual-band wireless network card to 11N mode.

有遇到设置2.4G，却无法切换到2.4G频段的，可使用本补丁文件，恢复2.4G频段。

--- package/network/services/hostapd/Makefile
+++ package/network/services/hostapd/Makefile
@@ -28,6 +28,7 @@
     CONFIG_PACKAGE_hostapd-mini \
     CONFIG_WPA_RFKILL_SUPPORT \
     CONFIG_DRIVER_WEXT_SUPPORT \
+    CONFIG_DRIVER_11N_SUPPORT \
     CONFIG_DRIVER_11AC_SUPPORT \
     CONFIG_DRIVER_11AX_SUPPORT \
     CONFIG_WPA_ENABLE_WEP
@@ -74,6 +75,10 @@
 
 STAMP_CONFIGURED:=$(STAMP_CONFIGURED)_$(CONFIG_WPA_MSG_MIN_PRIORITY)
 
+ifneq ($(CONFIG_DRIVER_11N_SUPPORT),)
+  HOSTAPD_IEEE80211N:=y
+endif
+
 ifneq ($(CONFIG_DRIVER_11AC_SUPPORT),)
   HOSTAPD_IEEE80211AC:=y
 endif
@@ -85,6 +90,7 @@
 DRIVER_MAKEOPTS= \
     CONFIG_ACS=$(CONFIG_PACKAGE_kmod-cfg80211) \
     CONFIG_DRIVER_NL80211=$(CONFIG_PACKAGE_kmod-cfg80211) \
+    CONFIG_IEEE80211N=$(HOSTAPD_IEEE80211N) \
     CONFIG_IEEE80211AC=$(HOSTAPD_IEEE80211AC) \
     CONFIG_IEEE80211AX=$(HOSTAPD_IEEE80211AX) \
     CONFIG_DRIVER_WEXT=$(CONFIG_DRIVER_WEXT_SUPPORT) \

--- package/network/services/hostapd/Config.in
+++ package/network/services/hostapd/Config.in
@@ -78,6 +78,10 @@
     select KERNEL_WIRELESS_EXT
     default n
 
+config DRIVER_11N_SUPPORT
+    bool
+    default n
+    
 config DRIVER_11AC_SUPPORT
     bool
     default n

--- package/network/services/hostapd/src/src/utils/build_features.h
+++ package/network/services/hostapd/src/src/utils/build_features.h
@@ -7,6 +7,10 @@
     if (!strcmp(feat, "eap"))
         return 1;
 #endif
+#ifdef CONFIG_IEEE80211N
+    if (!strcmp(feat, "11n"))
+        return 1;
+#endif
 #ifdef CONFIG_IEEE80211AC
     if (!strcmp(feat, "11ac"))
         return 1;

补丁文件下载：06_recover_11N.zip