clk: zynqmp: divider: Add missing description for 'max_div'

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

drivers/clk/zynqmp/divider.c:46: warning: Function parameter or member 'max_div' not described in 'zynqmp_clk_divider'

Cc: Michael Turquette <[e-mail]>
Cc: Stephen Boyd <[e-mail]>
Cc: Michal Simek <[e-mail]>
Cc: Rajan Vaja <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Signed-off-by: Lee Jones <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Acked-by: Michal Simek <[e-mail]>
Reviewed-by: Tero Kristo <[e-mail]>
Signed-off-by: Stephen Boyd <[e-mail]>

drivers/clk/zynqmp/divider.c

···
  * @is_frac:	The divider is a fractional divider
  * @clk_id:	Id of clock
  * @div_type:	divisor type (TYPE_DIV1 or TYPE_DIV2)
+ * @max_div:	maximum supported divisor (fetched from firmware)
  */
 struct zynqmp_clk_divider {
 	struct clk_hw hw;