libertas: move under marvell vendor directory

Part of reorganising wireless drivers directory and Kconfig.

Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
diff --git a/MAINTAINERS b/MAINTAINERS
index d72be8c..75ff743 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6708,7 +6708,7 @@
 MARVELL LIBERTAS WIRELESS DRIVER
 L:	libertas-dev@lists.infradead.org
 S:	Orphan
-F:	drivers/net/wireless/libertas/
+F:	drivers/net/wireless/marvell/libertas/
 
 MARVELL MV643XX ETHERNET DRIVER
 M:	Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>