lib/zlib: Split deflate and inflate states for DFLTCC

Currently deflate and inflate both use a common state struct. There are
several variables in this struct that we don't need for inflate, and
more may be coming in the future. Therefore split them in two separate
structs.
Apart from that, introduce separate headers for dfltcc_deflate and
dfltcc_inflate.

This commit is based on:
  https://github.com/zlib-ng/zlib-ng/commit/c592b1b

Link: https://lkml.kernel.org/r/20230126131428.1222214-7-zaslonko@linux.ibm.com
Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

lib/zlib_deflate/deflate.c

@@ -54,7 +54,7 @@
 
 /* architecture-specific bits */
 #ifdef CONFIG_ZLIB_DFLTCC
-#  include "../zlib_dfltcc/dfltcc.h"
+#  include "../zlib_dfltcc/dfltcc_deflate.h"
 #else
 #define DEFLATE_RESET_HOOK(strm) do {} while (0)
 #define DEFLATE_HOOK(strm, flush, bstate) 0
@@ -106,7 +106,7 @@ typedef struct deflate_workspace {
     deflate_state deflate_memory;
 #ifdef CONFIG_ZLIB_DFLTCC
     /* State memory for s390 hardware deflate */
-    struct dfltcc_state dfltcc_memory;
+    struct dfltcc_deflate_state dfltcc_memory;
 #endif
     Byte *window_memory;
     Pos *prev_memory;