hostapd: Add comment about '-i' parameter in hostapd.conf

Signed-off-by: Tim Kourt <tim.a.kourt@linux.intel.com>

hostapd/hostapd.conf

@@ -3,6 +3,8 @@
 
 # AP netdevice name (without 'ap' postfix, i.e., wlan0 uses wlan0ap for
 # management frames with the Host AP driver); wlan0 with many nl80211 drivers
+# Note: This attribute can be overridden by the values supplied with the '-i'
+# command line parameter.
 interface=wlan0
 
 # In case of atheros and nl80211 driver interfaces, an additional