ALSA: firewire-lib: add irq_target member into amdtp_domain struct

This commit is a preparation to handle several IR/IT contexts in the same
domain by tasklet context for one of the IT context. Such IT context is
stored to AMDTP domain structure as 'irq_target'.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20191018061911.24909-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/firewire/amdtp-stream.h

@@ -279,6 +279,8 @@ struct amdtp_domain {
 
 	unsigned int events_per_period;
 	unsigned int events_per_buffer;
+
+	struct amdtp_stream *irq_target;
 };
 
 int amdtp_domain_init(struct amdtp_domain *d);