PM / suspend: fix kernel-doc markup

Add parameter explanation to fix kernel-doc marks:

kernel/power/suspend.c:233: warning: Function parameter or member
'state' not described in 'suspend_valid_only_mem'
kernel/power/suspend.c:344: warning: Function parameter or member
'state' not described in 'suspend_prepare'

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
[ rjw: Change the proposed parameter descriptions. ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

kernel/power/suspend.c

@@ -224,6 +224,7 @@ EXPORT_SYMBOL_GPL(suspend_set_ops);
 
 /**
  * suspend_valid_only_mem - Generic memory-only valid callback.
+ * @state: Target system sleep state.
  *
  * Platform drivers that implement mem suspend only and only need to check for
  * that in their .valid() callback can use this instead of rolling their own
@@ -335,6 +336,7 @@ static int suspend_test(int level)
 
 /**
  * suspend_prepare - Prepare for entering system sleep state.
+ * @state: Target system sleep state.
  *
  * Common code run for every system sleep state that can be entered (except for
  * hibernation).  Run suspend notifiers, allocate the "suspend" console and