chore(xilinx): follow kernel doc format for functional documentation

For TF-A, there is no format specified for functional documentation.
For AMD-Xilinx platforms, following kernel-doc format for the functional
documentation to make sure AMD-xilinx documentation is align with
actual code.

For example use kernel-doc from linux to call:
<linux>/scripts/kernel-doc -man -v 1 >/dev/null file...

Signed-off-by: Prasad Kummari <prasad.kummari@amd.com>
Change-Id: Idcc9def408b6c8da35b36f67ef82fc00890e998c
diff --git a/plat/xilinx/zynqmp/pm_service/pm_client.c b/plat/xilinx/zynqmp/pm_service/pm_client.c
index 853e9e1..8cf29f0 100644
--- a/plat/xilinx/zynqmp/pm_service/pm_client.c
+++ b/plat/xilinx/zynqmp/pm_service/pm_client.c
@@ -157,10 +157,11 @@
 };
 
 /**
- * irq_to_pm_node - Get PM node ID corresponding to the interrupt number
- * @irq:	Interrupt number
+ * irq_to_pm_node - Get PM node ID corresponding to the interrupt number.
+ * @irq: Interrupt number.
  *
- * Return:	PM node ID corresponding to the specified interrupt
+ * Return: PM node ID corresponding to the specified interrupt.
+ *
  */
 static enum pm_node_id irq_to_pm_node(uint32_t irq)
 {
@@ -170,7 +171,8 @@
 
 /**
  * pm_client_set_wakeup_sources - Set all slaves with enabled interrupts as wake
- *				sources in the PMU firmware
+ *                                sources in the PMU firmware.
+ *
  */
 static void pm_client_set_wakeup_sources(void)
 {
@@ -227,10 +229,11 @@
 }
 
 /**
- * pm_get_proc() - returns pointer to the proc structure
- * @cpuid:	id of the cpu whose proc struct pointer should be returned
+ * pm_get_proc() - returns pointer to the proc structure.
+ * @cpuid: id of the cpu whose proc struct pointer should be returned.
  *
- * Return: pointer to a proc structure if proc is found, otherwise NULL
+ * Return: pointer to a proc structure if proc is found, otherwise NULL.
+ *
  */
 const struct pm_proc *pm_get_proc(uint32_t cpuid)
 {
@@ -242,10 +245,11 @@
 }
 
 /**
- * pm_get_proc_by_node() - returns pointer to the proc structure
- * @nid:	node id of the processor
+ * pm_get_proc_by_node() - returns pointer to the proc structure.
+ * @nid: node id of the processor.
  *
- * Return: pointer to a proc structure if proc is found, otherwise NULL
+ * Return: pointer to a proc structure if proc is found, otherwise NULL.
+ *
  */
 const struct pm_proc *pm_get_proc_by_node(enum pm_node_id nid)
 {
@@ -258,10 +262,11 @@
 }
 
 /**
- * pm_get_cpuid() - get the local cpu ID for a global node ID
- * @nid:	node id of the processor
+ * pm_get_cpuid() - get the local cpu ID for a global node ID.
+ * @nid: node id of the processor.
  *
- * Return: the cpu ID (starting from 0) for the subsystem
+ * Return: the cpu ID (starting from 0) for the subsystem.
+ *
  */
 static uint32_t pm_get_cpuid(enum pm_node_id nid)
 {
@@ -276,11 +281,14 @@
 const struct pm_proc *primary_proc = &pm_procs_all[0];
 
 /**
- * pm_client_suspend() - Client-specific suspend actions
+ * pm_client_suspend() - Client-specific suspend actions.
+ * @proc: processor which need to suspend.
+ * @state: desired suspend state.
  *
  * This function should contain any PU-specific actions
  * required prior to sending suspend request to PMU
  * Actions taken depend on the state system is suspending to.
+ *
  */
 void pm_client_suspend(const struct pm_proc *proc, uint32_t state)
 {
@@ -298,10 +306,11 @@
 
 
 /**
- * pm_client_abort_suspend() - Client-specific abort-suspend actions
+ * pm_client_abort_suspend() - Client-specific abort-suspend actions.
  *
  * This function should contain any PU-specific actions
- * required for aborting a prior suspend request
+ * required for aborting a prior suspend request.
+ *
  */
 void pm_client_abort_suspend(void)
 {
@@ -318,10 +327,12 @@
 }
 
 /**
- * pm_client_wakeup() - Client-specific wakeup actions
+ * pm_client_wakeup() - Client-specific wakeup actions.
+ * @proc: Processor which need to wakeup.
  *
  * This function should contain any PU-specific actions
- * required for waking up another APU core
+ * required for waking up another APU core.
+ *
  */
 void pm_client_wakeup(const struct pm_proc *proc)
 {