drbd: add major number to major.h

Since we have had a LANANA major number for years, and it is documented in
devices.txt, I think that this first patch can go upstream.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/major.h

@@ -145,6 +145,7 @@
 #define UNIX98_PTY_MAJOR_COUNT	8
 #define UNIX98_PTY_SLAVE_MAJOR	(UNIX98_PTY_MASTER_MAJOR+UNIX98_PTY_MAJOR_COUNT)
 
+#define DRBD_MAJOR		147
 #define RTF_MAJOR		150
 #define RAW_MAJOR		162