phy: rockchip: add naneng combo phy for RK3568

This patch implements a combo phy driver for Rockchip SoCs
with NaNeng IP block. This phy can be used as pcie-phy, usb3-phy,
sata-phy or sgmii-phy.

Signed-off-by: Yifeng Zhao <yifeng.zhao@rock-chips.com>
Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Tested-by: Peter Geis <pgwipeout@gmail.com>
Tested-by: Frank Wunderlich <frank-w@public-files.de>
Link: https://lore.kernel.org/r/20220208091326.12495-4-yifeng.zhao@rock-chips.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>