zram: add support for dict comp config

zram: add support for dict comp config

Handle dict=path 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/20240712051850.484318-17-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nick Terrell <terrelln@fb.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>