StandaloneMmPkg: Update YAML to ignore specific ECC files/errors

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3749

Update package YAML files to ignore ECC errors that are
already present.  These issues must be fixed in the future,
but should not block source code changes for these known
issues.

Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Sami Mujawar <sami.mujawar@arm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Supreeth Venkatesh <supreeth.venkatesh@arm.com>
Cc: Sean Brogan <sean.brogan@microsoft.com>
Cc: Bret Barkelew <Bret.Barkelew@microsoft.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Michael Kubacki <michael.kubacki@microsoft.com>
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
Acked-by: Ard Biesheuvel <ardb+tianocore@kernel.org>
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>

StandaloneMmPkg/StandaloneMmPkg.ci.yaml

@@ -5,6 +5,18 @@
 #  SPDX-License-Identifier: BSD-2-Clause-Patent
 ##
 {
+    "EccCheck": {
+        ## Exception sample looks like below:
+        ## "ExceptionList": [
+        ##     "<ErrorID>", "<KeyWord>"
+        ## ]
+        "ExceptionList": [
+            "4002", "HobConstructor"
+        ],
+        ## Both file path and directory path are accepted.
+        "IgnoreFiles": [
+        ]
+    },
     ## options defined .pytool/Plugin/CompilerPlugin
     "CompilerPlugin": {
         "DscPath": "StandaloneMmPkg.dsc"