sparc64: Fix prototype warning for alloc_irqstack_bootmem

Fix the following warning:
arch/sparc/kernel/setup_64.c:602:13: warning: no previous prototype for ‘alloc_irqstack_bootmem’

The function alloc_irqstack_bootmem had no users outside setup_64.c so
declare it static.

Signed-off-by: Sam Ravnborg <[email protected]>
Cc: Andreas Larsson <[email protected]>
Cc: David S. Miller <[email protected]>
Reviewed-by: Andreas Larsson <[email protected]>
Tested-by: Andreas Larsson <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Andreas Larsson <[email protected]>

Author: sravnborg

arch/sparc/kernel/setup_64.c

@@ -599,7 +599,7 @@ static void __init init_sparc64_elf_hwcap(void)
 		pause_patch();
 }
 
-void __init alloc_irqstack_bootmem(void)
+static void __init alloc_irqstack_bootmem(void)
 {
 	unsigned int i, node;