ArmPkg/ArmPkg.ci.yaml: Add PrEval CI config

Adds an entry to the package's CI configuration file that enable policy
5 for stuart_pr_eval. With this Policy, all INFs used by the package are
extracted from the provided DSC file and compared against the list of
changed *.inf (INF) files in the PR. If there is a match, stuart_pr_eval
will specify that this package is affected by the PR and needs to be
tested.

Signed-off-by: Joey Vagedes <joey.vagedes@gmail.com>

ArmPkg/ArmPkg.ci.yaml

@@ -5,6 +5,9 @@
 # SPDX-License-Identifier: BSD-2-Clause-Patent
 ##
 {
+    "PrEval": {
+        "DscPath": "ArmPkg.dsc",
+    },
     ## options defined .pytool/Plugin/LicenseCheck
     "LicenseCheck": {
         "IgnoreFiles": []