clk: qcom: branch: Add a helper for setting the enable bit

clk: qcom: branch: Add a helper for setting the enable bit

We hardcode some clocks to be always-on, as they're essential to the
functioning of the SoC / some peripherals. Add a helper to do so
to make the writes less magic.

Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20240212-topic-clk_branch_en-v7-1-5b79eb7278b2@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>