ACPI: cleanup: make disable_acpi() valid w/o CONFIG_ACPI

Len Brown <lenb@kernel.org> said:
> Okay, but better to use disable_acpi()
> indeed, since this would be the first code not already inside CONFIG_ACPI
> to invoke disable_acpi(), we could define the inline as empty and you could
> then scratch the #ifdef too.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Len Brown <len.brown@intel.com>

include/asm-i386/acpi.h

@@ -127,6 +127,7 @@ extern int acpi_irq_balance_set(char *str);
 #define acpi_ioapic 0
 static inline void acpi_noirq_set(void) { }
 static inline void acpi_disable_pci(void) { }
+static inline void disable_acpi(void) { }
 
 #endif	/* !CONFIG_ACPI */