[ath9k] Fix compilation on older gcc versions

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/drivers/net/ath/ath9k/ath9k_mac.c

 		REG_READ(ah, AR_IMR), REG_READ(ah, AR_IER));
 }
 
-void ath9k_hw_set_interrupts(struct ath_hw *ah, enum ath9k_int ints)
+void ath9k_hw_set_interrupts(struct ath_hw *ah, unsigned int ints)
 {
 	enum ath9k_int omask = ah->imask;
 	u32 mask, mask2;

src/drivers/net/ath/ath9k/mac.h

 
 struct ath_hw;
 struct ath9k_channel;
-enum ath9k_int;
 
 u32 ath9k_hw_gettxbuf(struct ath_hw *ah, u32 q);
 void ath9k_hw_puttxbuf(struct ath_hw *ah, u32 q, u32 txdp);
 
 /* Interrupt Handling */
 int ath9k_hw_intrpend(struct ath_hw *ah);
-void ath9k_hw_set_interrupts(struct ath_hw *ah, enum ath9k_int ints);
+void ath9k_hw_set_interrupts(struct ath_hw *ah, unsigned int ints);
 void ath9k_hw_enable_interrupts(struct ath_hw *ah);
 void ath9k_hw_disable_interrupts(struct ath_hw *ah);