feat(zynqmp): build pm code as library

Build Platform Management(PM) code as an Library.
Building PM code as library provides an option to switch to different
firmware interfaces like custom packages.

Change-Id: I872d45edf55ac83a6efb86591d12a0fef7b598cb
Signed-off-by: Amit Nagal <amit.nagal@amd.com>
Signed-off-by: Akshay Belsare <akshay.belsare@amd.com>
diff --git a/plat/xilinx/zynqmp/libpm.mk b/plat/xilinx/zynqmp/libpm.mk
new file mode 100644
index 0000000..4ceb576
--- /dev/null
+++ b/plat/xilinx/zynqmp/libpm.mk
@@ -0,0 +1,18 @@
+#
+# Copyright (c) 2023, Advanced Micro Devices, Inc. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+LIBPM_SRCS	:=	$(addprefix plat/xilinx/common/pm_service/,	\
+			pm_ipi.c)
+
+LIBPM_SRCS      +=      $(addprefix plat/xilinx/zynqmp/pm_service/,  \
+                        pm_svc_main.c 					\
+			pm_api_sys.c					\
+			pm_api_pinctrl.c				\
+			pm_api_ioctl.c					\
+			pm_api_clock.c					\
+			pm_client.c)
+
+$(eval $(call MAKE_LIB,pm))