ACPICA: Export acpi_tb_validate_rsdp().

This patch exports acpi_tb_validate_rsdp(), so that code duplication in
some ACPICA utilities can be reduced.
This patch also includes lint changes.

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/acpica/actables.h

@@ -49,6 +49,8 @@ acpi_status acpi_allocate_root_table(u32 initial_table_count);
 /*
  * tbxfroot - Root pointer utilities
  */
+acpi_status acpi_tb_validate_rsdp(struct acpi_table_rsdp *rsdp);
+
 u8 *acpi_tb_scan_memory_for_rsdp(u8 *start_address, u32 length);
 
 /*