bcache: move uapi header bcache.h to bcache code directory

The header file include/uapi/linux/bcache.h is not really a user space
API heaer. This file defines the ondisk format of bcache internal meta
data but no one includes it from user space, bcache-tools has its own
copy of this header with minor modification.

Therefore, this patch moves include/uapi/linux/bcache.h to bcache code
directory as drivers/md/bcache/bcache_ondisk.h.
Suggested-by: NArnd Bergmann <arnd@kernel.org>
Suggested-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NColy Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20211029060930.119923-2-colyli@suse.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

drivers/md/bcache/bcache.h

@@ -178,7 +178,6 @@
 
 #define pr_fmt(fmt) "bcache: %s() " fmt, __func__
 
-#include <linux/bcache.h>
 #include <linux/bio.h>
 #include <linux/kobject.h>
 #include <linux/list.h>
@@ -190,6 +189,7 @@
 #include <linux/workqueue.h>
 #include <linux/kthread.h>
 
+#include "bcache_ondisk.h"
 #include "bset.h"
 #include "util.h"
 #include "closure.h"

drivers/md/bcache/bset.h

@@ -2,10 +2,10 @@
 #ifndef _BCACHE_BSET_H
 #define _BCACHE_BSET_H
 
-#include <linux/bcache.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
 
+#include "bcache_ondisk.h"
 #include "util.h" /* for time_stats */
 
 /*

drivers/md/bcache/features.c

@@ -6,7 +6,7 @@
  * Copyright 2020 Coly Li <colyli@suse.de>
  *
  */
-#include <linux/bcache.h>
+#include "bcache_ondisk.h"
 #include "bcache.h"
 #include "features.h"
 

drivers/md/bcache/features.h

@@ -2,10 +2,11 @@
 #ifndef _BCACHE_FEATURES_H
 #define _BCACHE_FEATURES_H
 
-#include <linux/bcache.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
 
+#include "bcache_ondisk.h"
+
 #define BCH_FEATURE_COMPAT		0
 #define BCH_FEATURE_RO_COMPAT		1
 #define BCH_FEATURE_INCOMPAT		2