phy/cadence: Use of_device_get_match_data()

Use of_device_get_match_data() instead of open-coding it.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Minghao Chi (CGEL ZTE) <chi.minghao@zte.com.cn>
Link: https://lore.kernel.org/r/20220214020626.1714696-1-chi.minghao@zte.com.cn
Signed-off-by: Vinod Koul <vkoul@kernel.org>