ALSA: compress_driver.h: include sound/core.h explicitly

Fixes the following compilation error:

   include/sound/compress_driver.h: In function ‘snd_compr_drain_notify’:
   include/sound/compress_driver.h:177:2: error: implicit declaration of function ‘snd_BUG_ON’ [-Werror=implicit-function-declaration]
     if (snd_BUG_ON(!stream))

snd_BUG_ON() is defined in sound/core.h but the file is not included explicitly,
so include it.

Signed-off-by: Qais Yousef <qais.yousef@imgtec.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/include/sound/compress_driver.h b/include/sound/compress_driver.h
index 396e8f7..1e25310 100644
--- a/include/sound/compress_driver.h
+++ b/include/sound/compress_driver.h
@@ -27,6 +27,7 @@
 
 #include <linux/types.h>
 #include <linux/sched.h>
+#include <sound/core.h>
 #include <sound/compress_offload.h>
 #include <sound/asound.h>
 #include <sound/pcm.h>