[GFS2/DLM] use sysfs

With CONFIG_DLM=m, CONFIG_PROC_FS=n, and CONFIG_SYSFS=n, kernel build
fails with:

WARNING: "kernel_subsys" [fs/gfs2/locking/dlm/lock_dlm.ko] undefined!
WARNING: "kernel_subsys" [fs/dlm/dlm.ko] undefined!
WARNING: "kernel_subsys" [fs/configfs/configfs.ko] undefined!
make[1]: *** [__modpost] Error 1
make: *** [modules] Error 2

Since fs/dlm/lockspace.c and fs/gfs2/locking/dlm/sysfs.c use
kernel_subsys, they should either DEPEND on it or SELECT it.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

fs/dlm/Kconfig

@@ -5,6 +5,7 @@ config DLM
 	tristate "Distributed Lock Manager (DLM)"
 	depends on IPV6 || IPV6=n
 	select CONFIGFS_FS
+	select SYSFS
 	select IP_SCTP if DLM_SCTP
 	help
 	A general purpose distributed lock manager for kernel or userspace

fs/gfs2/Kconfig

@@ -38,6 +38,7 @@ config GFS2_FS_LOCKING_DLM
 	select IP_SCTP if DLM_SCTP
 	select CONFIGFS_FS
 	select DLM
+	select SYSFS
 	help
 	Multiple node locking module for GFS2