[ADC-GPIO]Enable ADC Gpio bridge configuration

Commit 1: configuration
Add support for ADC channel controlled by GPIO.
For example,ADC channel8, connected to CMOS battery, is controlled by a GPIO.
Need set 1 to gpio when Channel8 sampling, and set 0 to gpio when finish sampling.

Another Commit 2: Enabling ADC-Gpio Bridge

Tested:gpio will be created and exposed on dbus

Change-Id: I52bb79930bb2483239da57001312dacecd953ed2
Signed-off-by: Zhu, Yunge <yunge.zhu@linux.intel.com>
diff --git a/schemas/global.json b/schemas/global.json
index 09e5856..0068fed 100644
--- a/schemas/global.json
+++ b/schemas/global.json
@@ -312,6 +312,9 @@
                             },
                             "BindGpioIntrusion": {
                                 "type": "string"
+                            },
+                            "BridgeGpio": {
+                                "type": "integer"
                             }
                         },
                         "required": [