phy: ti: j721e-wiz: Drop OF node reference earlier for simpler code

Drop OF node reference immediately after using it in
syscon_node_to_regmap(), which is both simpler and typical/expected
code pattern.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240826-phy-of-node-scope-v1-10-5b4d82582644@linaro.org


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