hostapd: make ACS optional

Make ACS (Automatic Channel Selection) support in hostapd optional.
There's a clash of standard vs. propietary solutions, hence when hostapd
has builtin ACS support (standard) and it's enabled (channel=0 in the
config) this will preclude the propietary driver from using ACS (it
won't work at all).

See:
http://e2e.ti.com/support/wireless_connectivity/f/307/p/465333/1669270

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/hostapd/Config.in

@@ -14,6 +14,16 @@ config BR2_PACKAGE_HOSTAPD
 
 if BR2_PACKAGE_HOSTAPD
 
+config BR2_PACKAGE_HOSTAPD_ACS
+	bool "Enable ACS"
+	default y
+	help
+	  Enable support for standard ACS (Automatic Channel Selection).
+	  Some propietary drivers use a custom algorithm which requires
+	  channel to be set to '0' (which enables ACS in the config),
+	  causing hostapd to use the standard one which doesn't work
+	  for those cases.
+
 config BR2_PACKAGE_HOSTAPD_EAP
 	bool "Enable EAP"
 	depends on !BR2_STATIC_LIBS

package/hostapd/hostapd.mk

@@ -15,7 +15,6 @@ HOSTAPD_LICENSE_FILES = README
 HOSTAPD_CONFIG_SET =
 
 HOSTAPD_CONFIG_ENABLE = \
-	CONFIG_ACS \
 	CONFIG_FULL_DYNAMIC_VLAN \
 	CONFIG_HS20 \
 	CONFIG_IEEE80211AC \
@@ -45,6 +44,10 @@ HOSTAPD_CONFIG_DISABLE += CONFIG_EAP_PWD
 HOSTAPD_CONFIG_EDITS += 's/\#\(CONFIG_TLS=\).*/\1internal/'
 endif
 
+ifeq ($(BR2_PACKAGE_HOSTAPD_ACS),y)
+HOSTAPD_CONFIG_ENABLE += CONFIG_ACS
+endif
+
 ifeq ($(BR2_PACKAGE_HOSTAPD_EAP),y)
 HOSTAPD_CONFIG_ENABLE += \
 	CONFIG_EAP \