Support host selector using cpld definitions

Description:
- Support host selector using cpld definitions

Design:
- Because the current structure only supports config defined by GPIO
  (Yosemite V2), but there are also have the system (Yosemite V3.5)
  gets the host-selector's selection from CPLD.

- So this commit is to extend the current configuration to use CPLD
  definitions. Also, support adding event io from the register file
  which was exported from the CLD driver.

- For example with config json below:
{
   "cpld_definitions": [
        {
            "name": "HOST_SELECTOR",
            "i2c_address": 15,
            "i2c_bus": 12,
            "register_name": "uart-selection-debug-card",
            "max_position": 4
        }
   ]
}

Dependency:
- CLD driver is required (link: https://lore.kernel.org/lkml/20230117094425.19004-1-Delphine_CC_Chiu@Wiwynn.com/)

Test Case:
- When ocp debug card uart button is pressed the position property on
  dbus is correct.

Signed-off-by: Delphine CC Chiu <Delphine_CC_Chiu@wiwynn.com>
Change-Id: I6746afa6d905bd3c681e2921c643b3cd4cb9944c
diff --git a/inc/button_config.hpp b/inc/button_config.hpp
new file mode 100644
index 0000000..7678d25
--- /dev/null
+++ b/inc/button_config.hpp
@@ -0,0 +1,27 @@
+#pragma once
+#include "config.h"
+
+#include "cpld.hpp"
+#include "gpio.hpp"
+
+#include <nlohmann/json.hpp>
+
+#include <iostream>
+
+enum class ConfigType
+{
+    gpio,
+    cpld
+};
+
+// this struct represents button interface
+struct ButtonConfig
+{
+    ConfigType type;
+    std::string formFactorName;   // name of the button interface
+    std::vector<GpioInfo> gpios;  // holds single or group gpio config
+    CpldInfo cpld;                // holds single cpld config
+    std::vector<int> fds;         // store all the fds listen io event which
+                                  // mapped with the gpio or cpld
+    nlohmann::json extraJsonInfo; // corresponding to button interface
+};