phy: airoha: Add PCIe PHY driver for EN7581 SoC.

Introduce support for Airoha PCIe PHY controller available in EN7581
SoC.

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Tested-by: Zhengping Zhang <zhengping.zhang@airoha.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/20ac99aa8628d97778594f606681db7f868f24fe.1718485860.git.lorenzo@kernel.org


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