ALSA: seq: remove unused symbols

typedef struct snd_seq_real_time snd_seq_real_time_t;

typedef union snd_seq_timestamp snd_seq_timestamp_t;

/* maximum number of events dequeued per schedule interval */

#define SNDRV_SEQ_MAX_DEQUEUE		50

/* maximum number of queues */

#define SNDRV_SEQ_MAX_QUEUES		8

/* max number of events in memory pool */

#define SNDRV_SEQ_MAX_EVENTS		2000

/* default number of events in memory chunk */

#define SNDRV_SEQ_DEFAULT_CHUNK_EVENTS	64

/* default number of events in memory pool */

#define SNDRV_SEQ_DEFAULT_EVENTS	500