dt-bindings: clock: separate SDM845 GCC clock bindings

Separate qcom,gcc-sdm845 clock bindings from the clock-less
qcom,gcc.yaml, so that we can add required clocks and clock-names
properties.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20210409183004.1617777-2-dmitry.baryshkov@linaro.org
Signed-off-by: Stephen Boyd <sboyd@kernel.org>