firmware: qcom_scm: Always return devm_clk_get_optional errors

If devm_clk_get_optional throws an error, something is really wrong.
It may be a probe deferral, or it may be a problem with the clock
provider.

Regardless of what it may be, it should definitely not be ignored.
Stop doing that.

Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20230623-topic-scm_cleanup-v2-2-9db8c583138d@linaro.org


Signed-off-by: Bjorn Andersson <andersson@kernel.org>