phy: ti: Use IS_ERR_OR_NULL() to clean code

Use IS_ERR_OR_NULL() to make the code cleaner.

Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Link: https://lore.kernel.org/r/20211212142226.23674-1-linmq006@gmail.com


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