Refactor site_servo, site_vblock and site_gpio module into client/cros package(directory).

client/site_tests/hardware_GPIOSwitches/hardware_GPIOSwitches.py

 # -*- coding: utf-8 -*-
 #
 # Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 __author__ = 'nsanders@chromium.org (Nick Sanders)'
 
 import logging, os
 
 from autotest_lib.client.bin import test, utils
-from autotest_lib.client.common_lib import error, site_gpio
+from autotest_lib.client.common_lib import error
+from autotest_lib.client.cros import gpio
 
 class hardware_GPIOSwitches(test.test):
     version = 4
 
     def initialize(self):
-        self._gpio = site_gpio.Gpio(error.TestError)
+        self._gpio = gpio.Gpio(error.TestError)
 
     def gpio_read(self, name):
         try:
             return self._gpio.read(name)
         except:
             raise error.TestError(
                     'Unable to read gpio value "%s"\n'
                     '測試程式無法讀取 gpio 數值 "%s"' % (name, name))
 
     def run_once(self):
         self._gpio.setup()
         keyvals = {}
         keyvals['level_recovery'] = self.gpio_read('recovery_button')
         keyvals['level_developer'] = self.gpio_read('developer_switch')
         keyvals['level_firmware_writeprotect'] = self.gpio_read('write_protect')
 
         self.write_perf_keyval(keyvals)