zram: add support for dict comp config

Handle dict=path algorithm param so that we can read a pre-trained
compression algorithm dictionary which we then pass to the backend
configuration.

Link: https://lkml.kernel.org/r/20240902105656.1383858-17-senozhatsky@chromium.org


Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nick Terrell <terrelln@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>