firmware: qcom_scm: Always try to consume all three clocks

The code for handling more than 1 clock is a bit messy and requires
one to add new, SoC-specific compatibles if one wants to attach a clock.

Switch devm_clk_get to devm_clk_get_optional to prevent throwing it
from throwing errors when the clock is absent and defer checking the
clock requirements to dt schema.

This lets us get rid of compatibles that aren't necessary for backwards
compatibility *and* will hopefully prevent the addition of meaningless
new compatibles.

Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20230623-topic-scm_cleanup-v2-1-9db8c583138d@linaro.org


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