ACPI: Silence missing prototype warnings

Compiling with clang-16:

  drivers/acpi/acpi_lpit.c:142:6: error: no previous prototype \
  for function 'acpi_init_lpit' [-Werror,-Wmissing-prototypes]

  drivers/acpi/ioapic.c:212:6: error: no previous prototype \
  for function 'pci_ioapic_remove' [-Werror,-Wmissing-prototypes]

  drivers/acpi/ioapic.c:229:5: error: no previous prototype \
  for function 'acpi_ioapic_remove' [-Werror,-Wmissing-prototypes]

Include "internal.h" to silence them.
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/acpi_lpit.c

@@ -10,6 +10,7 @@
 #include <linux/acpi.h>
 #include <asm/msr.h>
 #include <asm/tsc.h>
+#include "internal.h"
 
 struct lpit_residency_info {
 	struct acpi_generic_address gaddr;

drivers/acpi/ioapic.c

@@ -24,6 +24,7 @@
 #include <linux/acpi.h>
 #include <linux/pci.h>
 #include <acpi/acpi.h>
+#include "internal.h"
 
 struct acpi_pci_ioapic {
 	acpi_handle	root_handle;