include/linux/lz4.h: add some missing macros

Currently, LZ4_DISTANCE_MAX and LZ4_DECOMPRESS_INPLACE_MARGIN are
defined in the erofs subsystem for LZ4 in-place decompression, which is
somewhat unsuitable since they should belong to the LZ4 itself and
may change with future LZ4 codebase updates.

Move them to include/linux/lz4.h to match the upstream LZ4 library [1].
No logic changes.

[1] https://github.com/lz4/lz4/blob/v1.10.0/lib/lz4.h#L670

Link: https://lkml.kernel.org/r/20250114130454.1191150-1-hsiangkao@linux.alibaba.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Cc: Yann Collet <yann.collet.73@gmail.com>
Cc: Nick Terrell <terrelln@fb.com>
Cc: Chao Yu <chao@kernel.org>
Cc: Yue Hu <zbestahu@gmail.com>
Cc; Jeffle Xu <jefflexu@linux.alibaba.com>
Cc: Sandeep Dhavale <dhavale@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

lib/lz4/lz4_compress.c

@@ -33,7 +33,6 @@
 /*-************************************
  *	Dependencies
  **************************************/
-#include <linux/lz4.h>
 #include "lz4defs.h"
 #include <linux/module.h>
 #include <linux/kernel.h>

lib/lz4/lz4_decompress.c

@@ -33,7 +33,6 @@
 /*-************************************
  *	Dependencies
  **************************************/
-#include <linux/lz4.h>
 #include "lz4defs.h"
 #include <linux/init.h>
 #include <linux/module.h>

lib/lz4/lz4defs.h

@@ -39,6 +39,7 @@
 
 #include <linux/bitops.h>
 #include <linux/string.h>	 /* memset, memcpy */
+#include <linux/lz4.h>
 
 #define FORCE_INLINE __always_inline
 
@@ -92,8 +93,7 @@ typedef uintptr_t uptrval;
 #define MB (1 << 20)
 #define GB (1U << 30)
 
-#define MAXD_LOG 16
-#define MAX_DISTANCE ((1 << MAXD_LOG) - 1)
+#define MAX_DISTANCE LZ4_DISTANCE_MAX
 #define STEPSIZE sizeof(size_t)
 
 #define ML_BITS	4

lib/lz4/lz4hc_compress.c

@@ -34,7 +34,6 @@
 /*-************************************
  *	Dependencies
  **************************************/
-#include <linux/lz4.h>
 #include "lz4defs.h"
 #include <linux/module.h>
 #include <linux/kernel.h>