irqchip/ath79-misc: Fix missing prototypes warnings

ath79_misc_irq_init() was defined but unused since commit 51fa4f8
("MIPS: ath79: drop legacy IRQ code"), so it's time to drop it.

The build also warns about a missing prototype of get_c0_perfcount_int().

Remove the stale leftover function and add the missing include.

Signed-off-by: Shiji Yang <yangshiji66@outlook.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/OSBPR01MB167032D2017645200787AAEBBC72A@OSBPR01MB1670.jpnprd01.prod.outlook.com

Author: DragonBluep

drivers/irqchip/irq-ath79-misc.c

@@ -15,6 +15,8 @@
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 
+#include <asm/time.h>
+
 #define AR71XX_RESET_REG_MISC_INT_STATUS	0
 #define AR71XX_RESET_REG_MISC_INT_ENABLE	4
 
@@ -177,21 +179,3 @@ static int __init ar7240_misc_intc_of_init(
 
 IRQCHIP_DECLARE(ar7240_misc_intc, "qca,ar7240-misc-intc",
 		ar7240_misc_intc_of_init);
-
-void __init ath79_misc_irq_init(void __iomem *regs, int irq,
-				int irq_base, bool is_ar71xx)
-{
-	struct irq_domain *domain;
-
-	if (is_ar71xx)
-		ath79_misc_irq_chip.irq_mask_ack = ar71xx_misc_irq_mask;
-	else
-		ath79_misc_irq_chip.irq_ack = ar724x_misc_irq_ack;
-
-	domain = irq_domain_create_legacy(NULL, ATH79_MISC_IRQ_COUNT,
-			irq_base, 0, &misc_irq_domain_ops, regs);
-	if (!domain)
-		panic("Failed to create MISC irqdomain");
-
-	ath79_misc_intc_domain_init(domain, irq);
-}