remoteproc: st: Simplify with dev_err_probe

Use dev_err_probe() to make error code handling simpler and handle
deferred probe.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Link: https://lore.kernel.org/r/20250111-b4-syscon-phandle-args-remoteproc-v1-3-73ed6fafa1e3@linaro.org


Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>