of: dynamic: Fix incorrect parameter name and provide missing descriptions

Fixes the following W=1 kernel build warning(s):

 drivers/of/dynamic.c:234: warning: Function parameter or member 'np' not described in 'of_attach_node'
 drivers/of/dynamic.c:286: warning: Function parameter or member 'np' not described in 'of_detach_node'
 drivers/of/dynamic.c:326: warning: Function parameter or member 'kobj' not described in 'of_node_release'
 drivers/of/dynamic.c:326: warning: Excess function parameter 'kref' description in 'of_node_release'

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: devicetree@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210318104036.3175910-3-lee.jones@linaro.org

drivers/of/dynamic.c

@@ -229,6 +229,7 @@ static void __of_attach_node(struct device_node *np)
 
 /**
  * of_attach_node() - Plug a device node into the tree and global list.
+ * @np:		Pointer to the caller's Device Node
  */
 int of_attach_node(struct device_node *np)
 {
@@ -281,6 +282,7 @@ void __of_detach_node(struct device_node *np)
 
 /**
  * of_detach_node() - "Unplug" a node from the device tree.
+ * @np:		Pointer to the caller's Device Node
  */
 int of_detach_node(struct device_node *np)
 {
@@ -318,7 +320,7 @@ static void property_list_free(struct property *prop_list)
 
 /**
  * of_node_release() - release a dynamically allocated node
- * @kref: kref element of the node to be released
+ * @kobj: kernel object of the node to be released
  *
  * In of_node_put() this function is passed to kref_put() as the destructor.
  */