wl1271: move wl12xx debugfs directory to under wiphy's debugfs

Use per-device debugfs path, so multiple devices won't collide.

in order to use wl->hw->wiphy->debugfsdir, we have to move the debugfs
creation from wl1271_debugfs_init() to wl1271_register_hw().

Reported-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Eliad Peller <eliad@wizery.com>
Signed-off-by: Luciano Coelho <luciano.coelho@nokia.com>
diff --git a/drivers/net/wireless/wl12xx/debugfs.c b/drivers/net/wireless/wl12xx/debugfs.c
index 402df14..2ac289e 100644
--- a/drivers/net/wireless/wl12xx/debugfs.c
+++ b/drivers/net/wireless/wl12xx/debugfs.c
@@ -423,7 +423,8 @@
 {
 	int ret;
 
-	wl->rootdir = debugfs_create_dir(KBUILD_MODNAME, NULL);
+	wl->rootdir = debugfs_create_dir(KBUILD_MODNAME,
+					 wl->hw->wiphy->debugfsdir);
 
 	if (IS_ERR(wl->rootdir)) {
 		ret = PTR_ERR(wl->rootdir);