clk: zynqmp: fix kernel doc

Add missing description of 'custom_type_flag' structure member.

Fixes: e605fa9c4a0c ("clk: zynqmp: Add support for custom type flags")
Signed-off-by: Rajan Vaja <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Stephen Boyd <[e-mail]>

drivers/clk/zynqmp/clk-zynqmp.h

···
  * @type:	Type of topology
  * @flag:	Topology flags
  * @type_flag:	Topology type specific flag
+ * @custom_type_flag: Topology type specific custom flag
  */
 struct clock_topology {
 	u32 type;