phy: rockchip-pcie: Use regmap_read_poll_timeout() for PCIe reference clk PLL status

Replace open-coded phy PCIe reference clk PLL status polling with
regmap_read_poll_timeout API. This change simplifies the code without
altering functionality.

Signed-off-by: Anand Moon <linux.amoon@gmail.com>
Link: https://lore.kernel.org/r/20241012071919.3726-4-linux.amoon@gmail.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>