drbd: stop including <asm-generic/kmap_types.h>

<linux/highmem.h> is the placace the get the kmap type flags, asm-generic
files are generic implementations only to be used by architecture code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

drivers/block/drbd/drbd_bitmap.c

@@ -29,7 +29,7 @@
 #include <linux/string.h>
 #include <linux/drbd.h>
 #include <linux/slab.h>
-#include <asm/kmap_types.h>
+#include <linux/highmem.h>
 
 #include "drbd_int.h"