Use better examples for MadWifi path in defconfig, clarify comments

MadWifi is unlikely to be in ../head relative to hostapd or
wpa_supplicant, as it would be inside the hostap git repository.
MadWifi sources are more likely to be in a directory called "madwifi"
and residing outside the hostap repository.  Using "madwifi" also
demonstrates that the top-level madwifi directory is needed.

hostapd/defconfig

@@ -17,7 +17,7 @@ CONFIG_DRIVER_HOSTAP=y
 
 # Driver interface for madwifi driver
 #CONFIG_DRIVER_MADWIFI=y
-#CFLAGS += -I../head # change to reflect local setup; directory for madwifi src
+#CFLAGS += -I../../madwifi # change to the madwifi source directory
 
 # Driver interface for Prism54 driver
 #CONFIG_DRIVER_PRISM54=y

wpa_supplicant/defconfig

@@ -51,8 +51,8 @@ CONFIG_DRIVER_HOSTAP=y
 
 # Driver interface for madwifi driver
 #CONFIG_DRIVER_MADWIFI=y
-# Change include directories to match with the local setup
-#CFLAGS += -I../madwifi/wpa
+# Set include directory to the madwifi source tree
+#CFLAGS += -I../../madwifi
 
 # Driver interface for Prism54 driver
 # (Note: Prism54 is not yet supported, i.e., this will not work as-is and is