md: move lots of #include lines out of .h files and into .c

This makes the includes more explicit, and is preparation for moving
md_k.h to drivers/md/md.h

Remove include/raid/md.h as its only remaining use was to #include
other files.

Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/faulty.c b/drivers/md/faulty.c
index 86d9adf..cc5d2cf 100644
--- a/drivers/md/faulty.c
+++ b/drivers/md/faulty.c
@@ -62,7 +62,10 @@
 #define	ModeShift	5
 
 #define MaxFault	50
-#include <linux/raid/md.h>
+#include <linux/blkdev.h>
+#include <linux/raid/md_u.h>
+#include <linux/raid/md_k.h>
+#include <linux/seq_file.h>
 
 
 static void faulty_fail(struct bio *bio, int error)