ACPI / hotplug: Make acpi_bus_hot_remove_device() internal

Notice that handle_root_bridge_removal() is the only user of
acpi_bus_hot_remove_device(), so it doesn't have to be exported
any more and can be made internal to the ACPI core.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 2c03aae..add408b 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -39,6 +39,8 @@
 #include <acpi/acpi_drivers.h>
 #include <acpi/apei.h>
 
+#include "internal.h"
+
 #define PREFIX "ACPI: "
 
 #define _COMPONENT		ACPI_PCI_COMPONENT