of: property: Provide missing member description and remove excess param

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

 drivers/of/property.c:1239: warning: Function parameter or member 'optional' not described in 'supplier_bindings'
 drivers/of/property.c:1366: warning: Excess function parameter 'dev' description in 'of_link_property'

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
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/20210318104036.3175910-6-lee.jones@linaro.org

drivers/of/property.c

@@ -1225,6 +1225,7 @@ static struct device_node *parse_##fname(struct device_node *np,	     \
  * @parse_prop.prop_name: Name of property holding a phandle value
  * @parse_prop.index: For properties holding a list of phandles, this is the
  *		      index into the list
+ * @optional: Describes whether a supplier is mandatory or not
  *
  * Returns:
  * parse_prop() return values are
@@ -1344,7 +1345,6 @@ static const struct supplier_bindings of_supplier_bindings[] = {
 
 /**
  * of_link_property - Create device links to suppliers listed in a property
- * @dev: Consumer device
  * @con_np: The consumer device tree node which contains the property
  * @prop_name: Name of property to be parsed
  *