enable file locking, very important, xbmc & pulseaduio does not start without it

target/linux/kernel.config

@@ -13,6 +13,8 @@ CONFIG_XFRM=y
 CONFIG_INET=y
 CONFIG_PROC_FS=y
 CONFIG_PROC_SYSCTL=y
+CONFIG_BLOCK=y
+CONFIG_FILE_LOCKING=y
 CONFIG_SYSFS=y
 CONFIG_TMPFS=y
 CONFIG_NLS=y