xilinx: Move IPI functions to common file

pm_service ipi functions can be used by other xilinx
platforms. So move it to common directory. Also change
node_id member type in pm_proc structure so it can be
used for versal where device IDs are used instead of
node IDs.

To accommodate this change header files are re-organized.

Signed-off-by: Tejas Patel <tejas.patel@xilinx.com>
Reviewed-by: Siva Durga Prasad Paladugu <siva.durga.paladugu@xilinx.com>
Signed-off-by: Jolly Shah <jollys@xilinx.com>
diff --git a/plat/xilinx/zynqmp/pm_service/pm_client.h b/plat/xilinx/zynqmp/pm_service/pm_client.h
index 0a34a07..adbb76f 100644
--- a/plat/xilinx/zynqmp/pm_service/pm_client.h
+++ b/plat/xilinx/zynqmp/pm_service/pm_client.h
@@ -21,6 +21,7 @@
 void pm_client_wakeup(const struct pm_proc *proc);
 enum pm_ret_status set_ocm_retention(void);
 enum pm_ret_status pm_set_suspend_mode(uint32_t mode);
+const struct pm_proc *pm_get_proc_by_node(enum pm_node_id nid);
 
 /* Global variables to be set in pm_client.c */
 extern const struct pm_proc *primary_proc;