clk/zynq/pll: Fix documentation for PLL register function

/**

 * clk_register_zynq_pll() - Register PLL with the clock framework

 * @np	Pointer to the DT device node

 * @name	PLL name

 * @parent	Parent clock name

 * @pll_ctrl	Pointer to PLL control register

 * @pll_status	Pointer to PLL status register

 * @lock_index	Bit index to this PLL's lock status bit in @pll_status

 * @lock	Register lock

 * Returns handle to the registered clock.

 */

struct clk *clk_register_zynq_pll(const char *name, const char *parent,

		void __iomem *pll_ctrl, void __iomem *pll_status, u8 lock_index,