[ACPI] unused exports in acpi

[Christoph H. <hc...@ls...>]

There's some acpi exports that seems to be unused, could someone who's
able to read the drivers/acpi/ mess doublecheck the list below?

acpi_acquire_global_lock
acpi_bus_receive_event
acpi_clear_event
acpi_dbg_layer
acpi_dbg_level
acpi_disable_event
acpi_enable_event
acpi_enter_sleep_state
acpi_enter_sleep_state_s4bios
acpi_get_next_object
acpi_get_possible_resources
acpi_get_sleep_type_data
acpi_get_system_info
acpi_get_timer
acpi_get_timer_duration
acpi_get_type
acpi_install_address_space_handler
acpi_install_gpe_block
acpi_os_create_semaphore
acpi_os_delete_semaphore
acpi_os_printf
acpi_os_read_pci_configuration
acpi_os_signal
acpi_os_signal_semaphore
acpi_os_sleep
acpi_os_stall
acpi_os_wait_semaphore
acpi_pci_irq_enable
acpi_release_global_lock
acpi_remove_address_space_handler
acpi_remove_gpe_block
acpi_set_current_resources
acpi_strict
acpi_ut_debug_print_raw