configuration: mtmitchell: add SysInletTemp sensor

Add SysInletTemp virtual sensor which is minimum of SysCabInletTemp,
MBInletTemp1, MBInletTemp2 and InletTemp.

Tested:
1. Run ipmitool sdr list and check value of SysInletTemp.

Change-Id: Id40de706e7c24cfa12b4ec8db541e371d38d7fac
Signed-off-by: Thang Q. Nguyen <thang@os.amperecomputing.com>
diff --git a/configurations/mtmitchell_mb.json b/configurations/mtmitchell_mb.json
index 2cf9b28..d218b67 100644
--- a/configurations/mtmitchell_mb.json
+++ b/configurations/mtmitchell_mb.json
@@ -2088,6 +2088,25 @@
                 "Units": "DegreesC"
             },
             {
+                "Name": "SysInletTemp",
+                "Sensors": [
+                    "SysCabInletTemp",
+                    "MBInletTemp1",
+                    "MBInletTemp2",
+                    "InletTemp"
+                ],
+                "Thresholds": [
+                    {
+                        "Direction": "greater than",
+                        "Name": "upper critical",
+                        "Severity": 1,
+                        "Value": 65
+                    }
+                ],
+                "Type": "Minimum",
+                "Units": "DegreesC"
+            },
+            {
                 "Address": "0x6a",
                 "Bus": 80,
                 "Name": "m2nvme0",