ACPI / x86: Export acpi_[un]register_gsi()

These functions might be called from modules as well so make sure
they are exported.

In addition, implement empty version of acpi_unregister_gsi() and
remove the one from pci_irq.c.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

arch/x86/kernel/acpi/boot.c

@@ -574,6 +574,12 @@ int acpi_register_gsi(struct device *dev, u32 gsi, int trigger, int polarity)
 
 	return irq;
 }
+EXPORT_SYMBOL_GPL(acpi_register_gsi);
+
+void acpi_unregister_gsi(u32 gsi)
+{
+}
+EXPORT_SYMBOL_GPL(acpi_unregister_gsi);
 
 void __init acpi_set_irq_model_pic(void)
 {

drivers/acpi/pci_irq.c

@@ -495,11 +495,6 @@ int acpi_pci_irq_enable(struct pci_dev *dev)
 	return 0;
 }
 
-/* FIXME: implement x86/x86_64 version */
-void __attribute__ ((weak)) acpi_unregister_gsi(u32 i)
-{
-}
-
 void acpi_pci_irq_disable(struct pci_dev *dev)
 {
 	struct acpi_prt_entry *entry;