clk: qcom: rcg2: Make hw_clk_ctrl toggleable

Certain SoCs use the HW_CLK_CTRL feature on some of the clocks they
host. This allows the clocks to be turned on automatically when a
downstream branch tries to change rate or config.

Make it togglable so that we can utilize this.

Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230517-topic-waipio-gpucc-v1-2-4f40e282af1d@linaro.org