ALSA: compress_offload: import DMA_BUF namespace

The compression offload code cannot be in a loadable module unless it
imports that namespace:

ERROR: modpost: module snd-compress uses symbol dma_buf_get from namespace DMA_BUF, but does not import it.
ERROR: modpost: module snd-compress uses symbol dma_buf_put from namespace DMA_BUF, but does not import it.
ERROR: modpost: module snd-compress uses symbol dma_buf_fd from namespace DMA_BUF, but does not import it.

Fixes: 04177158 ("ALSA: compress_offload: introduce accel operation mode")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Shengjiu Wang <shengjiu.wang@gmail.com>
Acked-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20241216093410.377112-1-arnd@kernel.org