hostapd: enable 802.11ac support

hostapd has supported 802.11ac for quite a while now (and it has been used in many OpenWrt/LEDE releases) so it should be safe to enable 802.11ac support in the build. This does not automatically turn it on at runtime, but just makes it available when a config file tries to turn it on (rather than spewing syntax errors about unrecognized directives).

---
 meta-oe/recipes-connectivity/hostapd/hostapd/defconfig | 3 +++
 1 file changed, 3 insertions(+)

index 2789640..a62bec4 100644
@@ -139,6 +139,9 @@ CONFIG_DRIVER_RADIUS_ACL=y
 # IEEE 802.11n (High Throughput) support
 CONFIG_IEEE80211N=y
 
+# IEEE 802.11ac (Very High Throughput) support
+CONFIG_IEEE80211AC=y
+
 # Remove debugging code that is printing out debug messages to stdout.
 # This can be used to reduce the size of the hostapd considerably if debugging
 # code is not needed.

1.9.4