sensor: Implement sensor "PRIORITY"

This commit introduces the `xyz.openbmc_project.Common.Priority`
interface to define the priority of sensors. If a sensor's priority
attribute is specified, this interface is created with the 'priority'
attribute. However, if the priority attribute is not specified, this
interface is not created.

The `xyz.openbmc_project.Common.Priority` interface is used to indicate
the priority level of fan sensors. It provides information about
primary and secondary RPM sensors for dual rotor fans, allowing for a
more specific description of the sensor's priority.

phosphor-dbus-interfaces commit:
https://gerrit.openbmc.org/c/openbmc/phosphor-dbus-interfaces/+/66779

Tested: Build phosphor-hwmon successfully

'''
1. Retrieve the priority level of the secondary sensor

busctl introspect xyz.openbmc_project.Hwmon-xxx .Hwmon1 \
/xyz/openbmc_project/sensors/fan_tach/fan1_1  xyz.openbmc_project.Common.Priority

NAME                                TYPE      SIGNATURE RESULT/VALUE FLAGS
.Priority                           property  u         1            emits-change writable

2. If the "PRIORITY" is not specified in the sensor's configuration file

busctl introspect xyz.openbmc_project.Hwmon-xxx .Hwmon1 \
/xyz/openbmc_project/sensors/fan_tach/fan1_0  xyz.openbmc_project.Common.Priority
NAME TYPE SIGNATURE RESULT/VALUE FLAGS

3. Change the sensor priority

busctl set-property xyz.openbmc_project.Hwmon-xxx.Hwmon1 \
/xyz/openbmc_project/sensors/fan_tach/fan1_1 xyz.openbmc_project.Common.Priority \
 Priority u 0

busctl introspect xyz.openbmc_project.Hwmon-xxx .Hwmon1 \
/xyz/openbmc_project/sensors/fan_tach/fan1_1  xyz.openbmc_project.Common.Priority
NAME                                TYPE      SIGNATURE RESULT/VALUE FLAGS
.Priority                           property  u         0            emits-change writable
'''

Change-Id: I7a226cf105756bc32e04f6724428d93e84dfb72a
Signed-off-by: Lakshmi Yadlapati <lakshmiy@us.ibm.com>
diff --git a/interface.hpp b/interface.hpp
index 6e2d71d..234af4c 100644
--- a/interface.hpp
+++ b/interface.hpp
@@ -1,6 +1,7 @@
 #pragma once
 
 #include <sdbusplus/server.hpp>
+#include <xyz/openbmc_project/Common/Priority/server.hpp>
 #include <xyz/openbmc_project/Control/FanPwm/server.hpp>
 #include <xyz/openbmc_project/Control/FanSpeed/server.hpp>
 #include <xyz/openbmc_project/Sensor/Accuracy/server.hpp>
@@ -29,6 +30,9 @@
 using StatusInterface = sdbusplus::xyz::openbmc_project::State::Decorator::
     server::OperationalStatus;
 using StatusObject = ServerObject<StatusInterface>;
+using PriorityInterface =
+    sdbusplus::xyz::openbmc_project::Common::server::Priority;
+using PriorityObject = ServerObject<PriorityInterface>;
 
 using SensorValueType = double;
 
@@ -45,6 +49,7 @@
     FAN_PWM,
     STATUS,
     ACCURACY,
+    PRIORITY,
 };
 
 // vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4