ArmPkg/ArmMonitorLib: Add ArmMonitorLib

The ArmMonitorLib provides an abstract interface to issue
an HyperVisor Call (HVC) or System Monitor Call (SMC) depending
on the default conduit.
The PcdMonitorConduitHvc PCD allows to select the default conduit.

Reviewed-by: Leif Lindholm <quic_llindhol@quicinc.com>
Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>

ArmPkg/Library/ArmMonitorLib/ArmMonitorLib.inf

@@ -0,0 +1,29 @@
+## @file
+#  Arm Monitor Library
+#
+#  Copyright (c) 2022, Arm Limited. All rights reserved.<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+##
+
+[Defines]
+  INF_VERSION                    = 1.29
+  BASE_NAME                      = ArmMonitorLib
+  FILE_GUID                      = F918DACB-FBB8-4CB6-A61D-08E75AF0E7CD
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = ArmMonitorLib
+
+[Sources]
+  ArmMonitorLib.c
+
+[Packages]
+  ArmPkg/ArmPkg.dec
+  MdePkg/MdePkg.dec
+
+[LibraryClasses]
+  ArmHvcLib
+  ArmSmcLib
+
+[Pcd]
+  gArmTokenSpaceGuid.PcdMonitorConduitHvc