[MIPS] Alchemy: remove useless prototypes.

#define EXT_INTC1_REQ1 5 /* IP 5 */

#define MIPS_TIMER_IP  7 /* IP 7 */

extern void set_debug_traps(void);

extern irq_cpustat_t irq_stat [NR_CPUS];

extern void mips_timer_interrupt(void);

static void setup_local_irq(unsigned int irq, int type, int int_req);

static void end_irq(unsigned int irq_nr);

static inline void mask_and_ack_level_irq(unsigned int irq_nr);

static inline void mask_and_ack_rise_edge_irq(unsigned int irq_nr);

static inline void mask_and_ack_fall_edge_irq(unsigned int irq_nr);

static inline void mask_and_ack_either_edge_irq(unsigned int irq_nr);

inline void local_enable_irq(unsigned int irq_nr);

inline void local_disable_irq(unsigned int irq_nr);

void	(*board_init_irq)(void);

static DEFINE_SPINLOCK(irq_lock);